Articles & Editorials
September 2009 - Volume 19 Number 9
Photos by Barry and Ruth Guimbellot
The moon has a heavy influence on the underwater world, from waves that meet the shore to the wanderings of marine creatures in the deep. This month's cover feature, "The Pull of the Moon: How Lunar Cycles Affect the Underwater World," explains how and why.
Get Down to Safety
By Alex Brylske Photo by Joseph C. Dovala
Robert Rossier’s Instructor Tips column this month addresses a topic that, unfortunately, receives almost no formal attention during most diver training courses. That’s a shame because, in my view, it’s the point in a dive at which problems are most likely to happen. These aren’t always life-threatening problems, but they’re problems that can ruin a dive and, if not addressed quickly, can lead to some very serious consequences. The topic I’m referring to is the simple act of floating on the surface.
The thing is, simply floating on the surface
isn’t always so simple. A diver on the
surface is on a thin line between two worlds: the realm of the air breathing and the realm of the aquatic. Rather than getting the best of both worlds, the diver is at a disadvantage. It’s sometimes difficult to get this point across to new divers because, after all, the surface is the place they feel most safe. But the reality is just the opposite. Although it may seem counterintuitive, good divers quickly learn that the best thing to do when it comes to bobbing around like a cork, especially in choppy conditions, is to remain in that state for as little time as possible.
The passage from the somewhat two-dimensional world of the atmosphere to the clearly three-dimensional world of the hydrosphere is usually best made quickly. To an experienced diver the surface is a netherworld — not quite here and not quite there. It’s a point you want to transition through smoothly and efficiently by being prepared to descend immediately upon gaining your buddy’s attention.
I remember in the ancient history that describes my own career as a diving educator, the original “Easy Diver” himself, Lou Fead, preached the dictum “look down to safety.” Truer words have never been spoken. Once in the water, a diver is no longer a land dweller. His scuba equipment, while providing adequate buoyancy for floating at the surface, is designed for peak performance underwater, not above. To a diver the surface is the realm of motion, compromised movement, confusion and, sometimes, nausea. With apologies to Lou, however, perhaps the dictum should be even more direct — not look down but get down to safety.

buddy lines
A Fan Far From Home
My son, Pvt. Christopher Brimmer, 21, is a fan of Dive Training. He is over in Iraq with a U.S. Army Engineers Battalion. Chris loves scuba diving. He has been diving at home in Minnesota lakes, and in Grand Cayman and Baja Mexico. He is an Advanced Open Water-certified diver. Your magazine helps remind him of home and of the good times he had diving. Also, our other son, Nick, 17, likes to read your magazine as well. We have been reading your publication for 11 years and just wanted to let you know that we really enjoy it.
Jerome T. Brimmer
Oakdale, Minnesota
Moray Backbone
Thanks for the world’s best scuba diving magazine! I’m an eight-year reader who anxiously awaits each new issue. I appreciate the quality and thoroughness of your articles and your willingness to dedicate several column inches, in two separate features, to reader comments and questions.
It is in this spirit of openness that I humbly offer a small correction to the otherwise excellent article on Long Island (Bahamas) by Linda Lee Walden. In her description of the Blue Tang dive site, she wrote “Invertebrates included a spotted moray and a spider crab.” The spotted moray eel (Gymnothorax moringa) is a proud member of subphylum Vertebrata — the price of admission for which is a backbone. Probably won’t matter to most readers, but to fellow science “geeks,” well….
Thanks again for your excellent publication.
Steve Pate
Oceanside, California
Exploding Tanks
In your June 2009 magazine, you published an article by Lynn Laymon warning of the danger of transporting scuba cylinders in the rear of a car on a hot day (“What It Looks Like When … Scuba Cylinders Have It Made in the Shade”).
Lynn’s points are all true. All except for the sense of danger and imminent disaster the article conveyed. This article reminds me of the periodic fuss made by new divers whenever someone publishes a picture of a diver wearing his or her mask on their forehead, regardless of circumstances. No masks on foreheads, no cylinders in the sun, no solo diving, always wear a snorkel — all dive lore that doesn’t really stand up to examination.
In an article in the Journal of the American Medical Association on February 10, 1999, the Centers for Disease Control (CDC) described experiments it conducted to determine the range of temperatures achievable in car interiors and trunks. Its interest, of course, wasn’t exploding scuba cylinders but the effects of rising heat on children left in parked cars on hot days. It found that the maximum temperature achievable inside a car on a day when the outside temperature was 100 degrees [38 degrees Celsius] was about 170 [77 C].
Charles’ law says that for every degree Fahrenheit that the temperature of a scuba cylinder rises, the pressure of the gas inside will increase about 5 psi. Let’s say you fill your scuba cylinder to 3,000 psi in an air-conditioned dive store where the temperature is, say, 70. Then you put the cylinder in your trunk and park it in the sun. If it’s a hot day and the CDC is correct, the temperature inside that cylinder will rise to maybe 170. The 170 (temperature after heating) minus 70 (temperature when filled) is a temperature rise of 100 degrees. Multiplying 100 times 5 psi per degree brings the pressure of your cylinder to 3,500 psi.
Burst discs are designed to burst at about 140 percent of the cylinder’s working pressure. A total of 140 percent of 3,000 psi is 4,200 psi, leaving a safety margin of 700 psi.
John Bowden
Marietta, Georgia
Dry Suit Guidelines
I just read your June 2009 issue and your dry suit diving instructions are in direct contradiction to PADI [Professional Association of Diving Instructors] guidelines. The use of the dry suit itself is the PADI method for buoyancy and the BC [buoyancy compensator] is used for surface buoyancy only. I am unsure what other scuba certification agencies state in this regard, but you might want to mention the difference between the various guidelines to keep the instructions simple and congruent if there are different instructions.
Patrick Patterson
Via e-mail
Cheers for Buddies
Your story on buddies brings up a topic I think sometimes goes underappreciated (“Buddies for Life: The Pleasures — and Potential Pitfalls — of Diving as a Couple,” July 2009, Dive Training). How much would we truly enjoy diving without someone to share the experience? I’ve been on hundreds of dives and not one ever seemed complete until I could talk about it with my dive buddy back on board the boat or my wife back home or my other diving friends. A big reason diving is fun is because it’s social. I hope we never lose sight of that.
Jerry Burroughs
Via e-mail
Electronic Gadget Groans
Congratulations on a substantive article on buoyancy “Positive, Negative, Neutral: Mastering the Basics of Buoyancy” (June 2009). As a sinker who always had a hard time attaining neutral buoyancy, I appreciate any guidance you can provide.
So much for the kudos.
Your article “Following the Pied Piper: Teaching Students About Underwater Audio Entertainment Systems” (June 2009) I found repugnant. OK, maybe it’s a generational issue. People my age do not need to be continually entertained by electronic gadgets. Why are we risking our lives in an alien environment if not to enjoy nature with only the gentle whisper of our air bubbles? I always considered diving the ultimate escape from the visual and audio pollution of life on the surface. And what happens if one of our fellow divers needs our help and we are so self-absorbed listening to music over high-tech headphones that we do not hear the drowning soul trying to get our attention by tapping on his/her air tank with a dive knife?
Thomas F. Johnson
Annandale, Virginia

Dive Observer
By Gene Gentrup
Underwater voyeurs are to vie for spots to dive Florida Keys reefs to view the annual coral "love affair" traditionally sparked by the August and September full moons.
The rare exchange of reproductive cells fascinates divers for the sheer volume of white excretion that seemingly fills the Atlantic Ocean around the continental United States' only living coral barrier reef, which parallels the Keys.
According to researchers, corals use multiple reproductive strategies. Nearly all large reef-building species release millions of gametes once a year in synchronized mass-spawning rituals. This "broadcast spawning" enables the immobile animals to send their eggs and sperm into the water in massive quantities.
When egg and sperm unite, the resulting larval-stage "planula" swims to the surface to drift in the current and grow. After some time — two days to two months — the planula settles to the bottom where it grows into a polyp. The polyp grows into a coral head by asexual budding that creates new polyps.
Such a copious delivery system is believed to maximize the chances of fertilization and at the same time overwhelm predators with more food than they can consume.
The cues triggering the annual phenomenon remain unclear, but are believed to be linked to water temperatures as well as lunar, tidal and 24-hour light cycles.
Scientists' observations indicate a strong connection between the coral spawn and seasonal lunar cycles. Though the polyp release cannot be guaranteed to happen on the exact date, the second of the 2009 full moons is scheduled for Friday, September 4.
Therefore, divers should be able to participate in remaining coral spawning night dives September 2, 3 and 4.
To learn more about the 2009 coral spawn in the Florida Keys, contact a Keys dive operator or visit the Florida Keys & Key West Web site at

Diving Notes and News
New Jersey has stopped converting old stainless steel subways into artificial reefs because the cars are deteriorating too quickly, officials say.
The program originally called for dumping up to 600 former New York City subway cars into the ocean. About 100 of the 35,000-pound cars were submerged on two of the state's 15 offshore reefs before the program was suspended in February.
State Environmental Protection Department spokeswoman Darlene Yuhas says a survey of 48 cars placed on the Atlantic City Reef found only two had remained intact. The U.S. Environmental Protection Agency had estimated the cars would serve as a reef for up to 30 years.
No other problems have been found with a different type of subway car. The "Redbird" was made of steel instead of stainless steel and are about half the weight of the newer cars. They have been used on New Jersey reefs since 2003.
About 160 cars had been earmarked for three other New Jersey reefs, including the Shark River, Garden State South and Deepwater reefs, before the termination.
Officials said the submerged subway cars pose no threat and still provide some habitat though not the quality of habitat that meets state standards.
The first stainless steel cars in New Jersey waters were deployed off Atlantic City on April 3, 2008, and state officials sent scuba divers to check them in November. The monitoring prevented as many as 500 more cars from being deployed.
The stainless steel subway cars were expected to be the major addition this summer to the reefs, which are supported by divers and recreational fishermen. The state still has plans to sink a surf clam boat, 500,000 cubic yards (384,615 cubic m) of rocks and 500 prefabricated reef balls.
The Atlantic City reef is located 8.8 nautical miles (14 km) offshore of the Absecon Inlet, has a depth range of 50-90 feet (15-27 m) and is 4 square miles (10 sq km) in size. Also on the Atlantic City reef are Redbird subway cars, concrete, reef balls, telecommunication cables, army tanks, tires and various vessels all of which total just under 65,000 cubic yards (50,000 cubic m) of reef material.
For more information, check out
Since the May 27 sinking of the 523-foot-long Gen. Hoyt S. Vandenberg in the Florida Keys National Marine Sanctuary, a clearer picture has emerged of what divers will see at the site.
The Vandenberg is now the second-largest artificial reef in the world, and sits in nearly 150 feet (45 m) of water about seven miles (11 km) off Key West.
Florida Keys tourism officials provide this description of what divers will see: "The top of the superstructure, at a depth of about 50 feet [15 m], is visible from the surface, punctuated by the platformlike kingpost and one of the iconic parabolic dish antennae, glowing white and beckoning from below. Once the algae and soft corals grow and cover the hull, the white will fade to blend in with colors of the ocean life. Over the course of decades the ship's hull will be densely populated with species of coral, sponges, invertebrates, sea fans and sea whips.
"For safety and ease, divers descend along a lead line attached to one of the wreck's mooring lines, a half dozen of which have been placed intermittently along the 523 feet [158 m] that stretch from bow to stern. All dive spots along the superstructure are open, free from obstruction and easy to maneuver around during a dive. Vandenberg is a wreck of plenty, and several return trips are required to appreciate its length — nearly two football fields. Starting from a vantage point at the bow and moving aft, divers can pause at the kingpost and foremast, sure to be a popular underwater photo op for dive buddies, and a rest platform or safety stop during ascension from deeper dives. Continuing aft, neutral divers can hang at anywhere from 55 to 70 feet and see the bridge, and a telescope — part of the star-tracking systems during the Vandenberg's active duty — mounted on top of the wheelhouse.
"Behind the bridge and the main mast is the smaller of the two iconic radar dishes; next, the No. 1 barbette, a heavy steel structure in the shape of a pedestal used as protection for artillery gun turrets on military ships. Aft of the No. 1 barbette is the larger radar dish, which in the 1999 movie ‘Virus' provided an explosive sequence when a laser from space blew the dish off the ship. Farther aft is the trimmed part of the foremast with the crow's nest, as well as the bottom half of the ship's smokestack. The other half, trimmed to about 20 feet [6 m] tall for an even profile along the ship's structure, now sits atop the stern's weather balloon hangar, dubbed the ‘underwater Margaritaville' — a clubhouse tribute to the Parrot Head fans of entertainer Jimmy Buffett, who contributed to the Vandenberg project. Though the Vandenberg delivers as a safe, enjoyable dive for certified divers at most experience levels, it is primarily recommended for properly certified and trained advanced and wreck divers."
Divers in San Diego will have some stories to tell after shallow-water encounters with Humboldt squid — 5-foot-long creatures with sharp beaks and tentacles that normally ply much deeper waters.
Thousands of them recently invaded the waters off San Diego, surprising divers and washing up dead on beaches.
Some reports said the squid tugged at dive masks and "roughed up" some divers although there were no reports of injuries. The squid, which can grow up to 100 pounds (45 kg), are native to the deep waters off Mexico, where they have been known to attack humans.
Scientists are not sure what triggered the swarm off the Southern California coast. A similar invasion occurred off San Diego in 2005 and, in 2002, thousands of squid washed up on the beaches. Some experts believe the squid may have established a year-round population off California at depths of 300-650 feet (91-197 m) and follow their prey when they move to shallow water.
Panama City, Florida, has a new dive site. The tugboat Red Sea was sunk June 24 as an artificial reef 5.5 miles (9 km) from Panama City Beach in the Gulf of Mexico.
The oceangoing tug is 130 feet (39 m) long and 30 feet (9 m) wide. It was built in Philadelphia in 1929 and now sits on sand 75 feet (23 m) below the surface. The reef is near another dive site, the USS Strength.
Airline Bag Fees INCREASED
Airlines are adding surcharges as they struggle through the recession.
United, Delta, US Airways and Continental Airlines this year have added a $5 surcharge to bag fees paid at the airport.
Passengers flying those airlines can avoid the surcharge simply by paying the bag fee online.
With the surcharge, most of the major airlines now charge $20 for the first bag and $30 for the second. Southwest Airlines does not charge customers for first or second checked bags. JetBlue does not charge for the first checked bag.

El Niño has arrived, federal scientists have announced.
The phenomenon, a periodic warming of central and eastern tropical Pacific waters, can be a mixed blessing. On one hand, scientists say, El Niño can help to suppress Atlantic hurricane activity. In the United States, it typically brings beneficial winter precipitation to the arid Southwest, less wintry weather across the North, and a reduced risk of Florida wildfires.
Other El Niño influences have included damaging winter storms in California and increased storminess across the southern United States.
An El Niño event may significantly diminish ocean productivity off the west coast by limiting weather patterns that cause upwelling, or nutrient circulation in the ocean. These nutrients are the foundation of a vibrant marine food web and could negatively affect food sources for several types of fish and marine mammals.
El Niños occur on average every two to five years and typically last about a year. The climate phenomenon affects global weather, ocean conditions and marine fisheries. Scientists expect this El Niño to continue developing during the next several months, with further strengthening possible. The event is expected to last through winter 2009-10. For more information, visit
Study Shows Ocean Health Plays Vital Role in Coral Reef Recovery
A new study shows that bleached corals bounce back to normal growth rates more quickly when they have clean water and plentiful sea life at their side.
The new research study led by scientists at Scripps Institution of Oceanography at the University of California at San Diego suggests that by improving overall ocean health, corals are better able to recover from bleaching events, which occur when rising sea temperatures force corals to expel their symbiotic algae, known as zooxanthellae. Coral bleaching is a phenomenon that is expected to increase in frequency as global climate change increases ocean temperatures worldwide.
The new findings, published in the July 22 issue of the journal PLoS ONE, show that following a major bleaching event Mountainous star coral (Montastraea faveolata) on various reefs in Honduras and Belize was able to recover and grow normally within two to three years when the surrounding waters and reef were relatively healthy. In comparison, those corals living with "excessive local impacts," such as pollution, were not able to fully recover after eight years.
"You can imagine that when you are recovering from a sickness, it will take a lot longer if you don't eat well or get enough rest," said Jessica Carilli, Scripps graduate student and lead author on the study. "Similarly, a coral organism that must be constantly trying to clean itself from excess sediment particles will have a more difficult time recovering after a stressful condition like bleaching."
Carilli and colleagues analyzed 92 coral cores collected from four reef sites off the coast of Honduras and Belize. The cores were collected from reefs with different degrees of local stress from pollution, overfishing and sediment and nutrient runoff from land. By using X-rays, the researchers were able to examine the coral's annual growth rate records since 1950, including the time before and after a major bleaching event in 1998.
"It is clear that Mesoamerican corals really fell off a cliff in 1998 — nearly everybody suffered mass bleaching," said Dick Norris, Scripps professor of paleooceanography and co-author of the study. "There are no pristine reefs in the region, but the ones in the best shape clearly are more resilient than those that are long-suffering. It shows that a little improvement in growing conditions goes a long way in recovering coral health."
Corals are widely considered to be barometers for global warming and are important for biodiversity in the world's oceans. Coral reefs thrive in warm
tropical oceans under just the right conditions that include moderate temperatures and low nutrient and sediment input from land-based sources.
Protecting reef health from local sources of stress, such as runoff, can improve resilience to global warming stress.
Coral bleaching occurs when the tiny zooxanthellae, living with the tissues of coral polyps, which are responsible for their vibrant colors, are lost and the coral turns white in color.
The fastest recovering were corals collected from Turneffe Atoll, which is farther offshore than the main Belize Barrier Reef and Cayos Cochinos, a marine biological reserve off the northern coast of Honduras.
Florida's recreational harvest season for bay scallops began July 1 and continues through September 10.
Open scalloping areas on Florida's Gulf coast extend from the west bank of the Mexico Beach Canal in Bay County to the Pasco-Hernando county line near Aripeka. Bay scallops can be taken only within the allowable harvest areas.
Possessing bay scallops while in or on state waters outside the open harvest areas, or to land bay scallops outside the open areas, is illegal. Daily limits of 2 gallons (7.6 liters) of whole bay scallops in the shell or 1 pint (0.47 liters) of bay scallop meat per person during the open season is enforced. In addition, no more than 10 gallons (38 liters) of whole bay scallops in the shell or one-half gallon of bay scallop meat may be possessed aboard any vessel at any time.
Bay scallops must be harvested by hand or with a landing or dip net, and bay scallops may not be harvested for commercial purposes. Unless otherwise exempt, a regular Florida saltwater fishing license is required when using a boat to harvest scallops. If wading from shore, you will need a regular Florida saltwater fishing license or the new shore-based license.
Divers and snorkelers must display a "divers down" flag while in the water. Boaters must stay at least 100 feet (30 m) away from a dive flag in a river, inlet or channel. In open waters, boaters must stay 300 feet (91 m) away from a dive flag.
For more information on dive flag requirements, visit SANDREGS/Rules_Boat.htm#flag.

The USC Catalina Hyperbaric Chamber is offering its annual Emergency Response Diver Course for all divers who want to improve their rescue skill. This year the Emergency Response Diver (ERD) will be offered October 18-23.
The Emergency Response Diver course is designed to prepare divers with the knowledge, skills and practice to handle emergency situations. The course is presented by Gordon Boivin, former senior instructor for the Canadian Coast Guard, and Karl Huggins, director for the USC Catalina Hyperbaric Chamber.
Special topics include the best techniques for beach and boat rescues; the best way to handle a victim in the water; how to administer effective CPR and first aid; how to make the best use of emergency oxygen; how to efficiently manage the diving accident scene; and methods for dealing with hypothermia, near drowning and other diving maladies.
Tuition for the ERD course is $675, which includes all instruction, five nights of housing at the USC Catalina Island facility and all meals.
For more information, see the chamber's Web site at hyperbaric/chamber or contact the chamber at USC Catalina Hyperbaric Chamber, P.O. Box 5069, 1 Big Fisherman's Cove, Two Harbors, CA 90704; or call (310) 510-4020.

IN New Jersey
Tom Gormley's 208-page paperback comes with 138 black-and-white photos and 44 maps to detail the 127 miles (203 km) of shoreline and many more miles of inlets, bays, rivers and lakes that provide opportunities for shore diving in the Garden State. The new book details how to find the sites and what divers can expect to see once underwater. Maps, and in many cases GPS numbers, help divers locate the exact entry spots. Any dangers such as currents and boat traffic are noted, as well as how best to coordinate with local authorities, if necessary.
Also included are sections on how to shore dive, seasons, dive skills, marine life, night diving, photography, lobster hunting and spearfishing. There are also sections on shore diving in surrounding states, and lists of dive clubs and environmental organizations.
Gormley has been diving in the Northeast and Caribbean waters for three decades. He became a dive instructor in 1994 and teaches beginner through divemaster students. In 1997 he helped form Divers Anonymous Scuba Club, and has been the president for the past 11 years.
For more information about the book by AquaQuest Publications, visit your local dive shop.

always learning
More Like Marvin:
What I Learned in a Hawaiian Elementary School
Story and photos by Marty Snyderman
In our society, old is the antithesis of hip. Seeing as how I'll turn 6-0 in a matter of months, I know this to be true.
To soften the blow of aging, people sometimes give recognition to those of us who are getting a little long in the tooth. In my case, last fall I was honored as one of two recipients of the dive industry's Reaching Out Award and in April of this year, along with another dozen or so San Diegans, I was recognized as a pioneer in the San Diego diving community by the San Diego Underwater Photographic Society.
While that type of recognition doesn't regrow hair, it is very nice to receive. No doubt, recognition makes it easier for my voice to be heard in the public arena, and the important question becomes, "What am I going to do with my voice?" It is a question many of us ask ourselves.
For many years I have been aware that writing a monthly column in this magazine is not a right but a privilege. Every month a lot of people read what I have to say about underwater photography, marine wildlife and marine conservation. These are issues that are near and dear to my heart. I don't expect everyone to hang on my every word, but I do appreciate having my voice heard. Being heard gives me the opportunity to make a difference.
I am equally convinced that making an important contribution does not require a large audience. Perhaps my published comments can energize others to get involved, but almost always the real difference makers are those who get involved at the grassroots level. It seems to me that the influence that converts an author's published words into someone's deeds often comes from common people.
Usually the people interacting at the local level do not receive the same degree of public recognition that I have enjoyed, but often they are the ones doing the real work. I get paid to think and type. They do the legwork and usually provide the labor and often some of the money. Sometimes those people get a piece of paper or a letter of thanks, but many times they get nothing more than the satisfaction of knowing they are doing their part. It takes those often overlooked and underappreciated grassroots workers to get the job done. I was reminded of this a few weeks ago when I dived with and spoke to kids at a private school on the Hawaiian island of Kauai.
What Marvin Wants
A few months ago, as I was wrapping up my presentation at the Hawaiian Islands Recreational Scuba Association's (HIRSA) annual Industry Day meeting, one of the attendees, Marvin Otsuji from Kauai, invited me to give a presentation at a local school. I enjoy speaking to kids of all ages, so I agreed, provided I could fit a presentation into my schedule the next time I was visiting Kauai.
Marvin wants school kids on Kauai to see how diving and being knowledgeable about the oceans can help connect them to the world that lies beyond the shorelines of Kauai. He didn't want me to limit my presentation to marine wildlife or underwater photography. Marvin wanted me to talk with the kids about the value of Kauai's marine resources. He wanted me to address how knowing about the oceans and being informed about marine issues has provided career opportunities for people like me, and how it might do the same for the kids I would meet.
Marvin also wants to help cultivate the school's dive club; not for profit, but to enhance the lives of the kids and other locals. He wants them to realize how lucky they are to be blessed with their marine resources, and that those resources should be appreciated and protected. He wants them to know that knowledge about those resources can help open doors to a great big world beyond Kauai's shores.
I should have known Marvin's intentions would be along those lines. I have known him for several years and he has always been involved in one way or another in trying to make sure Kauai's kids see the big picture of Kauai as part of a much larger, opportunity-filled world. Marvin strongly believes that while Kauai is a wonderful place to live, if you don't know anyplace else or any other "way of life," the island and its resources can easily be taken for granted.
Marvin is the kind of guy who isn't too inclined to take "no" for an answer. I imagine that what Marvin wants, he usually gets. By the time Marvin quit talking I had no choice but to graciously accept his invitation to meet and dive with the kids at Kauai's Island school. We set the date to follow a photography seminar I taught in Kona on the Big Island. Marvin arranged things with the school, made flight reservations and I was on my way.

Going Back to School
A few short months later I returned to Kauai as promised. I dived with members of the Island School's Dive Club on one of Marvin's boats, and the following day I gave a presentation to about 200 sixth- through 12-graders and faculty members at a school assembly that was arranged by Marvin and the school's adult dive club coordinators. As I showed slides and video clips, I spoke about how my love for the sea led to my career, how my career has taught me to appreciate the oceans' resources — and how my career has been my ticket to see the world and gain a better understanding of people and cultures from distant lands.
There is no way I can be certain that I got my points across, or that I influenced anyone's life that day. That's hard to figure. But I do know this: I might have succeeded. I might have reached one kid, or two, or perhaps a handful. I am absolutely certain that I would not have reached any if I hadn't tried and if Marvin hadn't put forth the time, effort and funding he provided to arrange and coordinate my visit.
The Lesson
Without this article no one outside of a few teachers, parents and school kids would likely ever know that Marvin went to the trouble and expense of making my visit happen. People in his position usually don't get the recognition and thanks that they should, but without his contribution the dives and the presentation never would have happened. And maybe, just maybe, we struck a chord with one kid. Wouldn't that be a great thing?
Ultimately, making a meaningful contribution is not about seeing your name in print or getting public kudos. The meaningful part is the contribution. Sure, it's a cliché, but I am convinced that the only way to win the war for marine awareness and other causes is for people at every level to make the personal commitment to be part of the solution.
To all of those who give presentations to schools and organizations within your local community, I know your name doesn't always get into print, but plenty of people benefit from your good deeds. So do a lot of creatures that have no voice. None of us are likely to hit a home run every time we swing, but you will never hit one if you don't take your turn at bat. The world needs all the Marvins it can get. How about making the commitment to become the next Marvin by getting involved in your local community? You'll be glad you did.
How to be a Marvin
You don't need to be a certified classroom teacher to be an effective educator. Schools are always interested in hosting guest speakers and classroom volunteers. And it's easier than you might imagine. Oceans For Youth, a nonprofit foundation designed to promote ocean education, has a host of educational resources available.
Simply visit to learn more.

no dumb questions
After Heart Surgery, Deco Stop Concerns,
More on Bounce Diving
By Alex Brylske
Q:Reader Francis Mallon had a short but important question about an issue of increasing concern, given the aging diving population. "Can a person who has had bypass surgery dive with restrictions?"

The short answer is "possibly," and, of course, depends on individual circumstances. Certainly, many divers have had the procedure performed, and have been cleared for diving after this and other forms of heart surgery. That's probably not surprising given that surgeons perform these procedures by the hundreds every day to the tune of more than 500,000 times annually. Diving and other forms of strenuous exercise are possible after bypass surgery because, if the procedure is successful, the patient should become free of the symptoms of coronary artery disease, and the heart muscle should receive normal blood flow and oxygen.
In medical recommendations, the "Guidelines for Recreational Scuba Diver's Physical Examination," which are part of the RSTC (Recreational Scuba Training Council) Medical Statement that many divers complete and sign prior to entering a scuba class clearly identify "history of coronary artery bypass grafting (CABG)" under the "relative risk" category. But opinions vary. I know a number of physicians who automatically disqualify as a diving candidate any patient who has undergone any form of bypass or similar procedure. However, others are more lenient with patients who were divers prior to the procedure, and wish to return to diving. Clearly, it's an individual matter.
The final call on the fitness-to-dive issue is between the patient and his or her cardiologist. The concern is that someone who has undergone a bypass may have suffered significant cardiac damage prior to having the surgery. Therefore, it's the post-operative cardiac function of the patient that dictates their fitness for diving.
According to the Divers Alert Network (DAN), anyone who has had open-chest surgery needs appropriate medical evaluation prior to scuba diving. After a period of stabilization and healing (6-12 months is usually recommended), the individual should have a thorough cardiovascular evaluation before being cleared to dive. He or she should be free of chest pain and have normal exercise tolerance, as evidenced by a normal stress EKG test. If there is any doubt about the success of the procedure or how open the coronary arteries are, the individual should refrain from diving. If you'd like more information, an excellent overview is offered by Dr. James Caruso in an article,
"Cardiovascular Fitness and Diving," available on DAN's Web site (www.
Q:Bo Pruitt wrote with a much longer question about losing your buddy. "Recently I noticed that I am coming across a subject that shows up in every one of my specialty course manuals and also shows up in Dive Training. The subject is lost buddies and the procedures for locating them. My quandary is this: We are usually instructed to look high and low for your buddy, spin in a 360-degree pattern and make absolutely sure they are nowhere in sight. Then, as a last result, return to the surface and hopefully you'll reunite. However, articles and the textbook instructions keep telling us to make a slow ascent to the surface to find them, but they never mention safety stops while completing this procedure. So my question is this: Do you make a safety stop while trying to locate a lost buddy at the surface or not? Will we put ourselves at risk of decompression illness if we skip the safety stop? Is it correct to go straight to the top with no safety stop? And if we do go straight to the surface to locate our buddy, should we both redescend and make a delayed safety stop to lower the DCI risk? I feel like this is a very valid question because I do want to help any lost buddy, but I don't want to seriously injure myself in the process. I can see this being of little concern in shallow depth, say 30 feet [9 m], but what if we are at 100 feet [30 m]?"

A:This is an excellent question and you seem to have raised all the salient issues. First, as always, your safety is always paramount, even to that of your buddy's. Certainly, you want to be a responsible buddy, but that doesn't mean you should put yourself at risk to relocate an errant buddy. Regardless of why you have to ascend, an ascent is an ascent. So, except in an emergency, the same rules and recommendations apply. As you note, given the relatively mild decompression stress, I'd have no qualms about ascending slowly but immediately from a shallow depth — say 30 feet (9 m) or less — without a safety stop. However, in my opinion, anything deeper should involve a stop, even if the reason for surfacing involves a lost buddy procedure. The laws of physics are not suspended just because you need to find your buddy, so the risk of decompression sickness is no less.
You also raise an interesting question about returning to depth to perform a safety stop after you've surfaced to reunite with your buddy (who hopefully has surfaced as well). The idea of "making up" a missed stop was probably inspired by a procedure used by the U.S. Navy (and once taught in recreational scuba courses) for what was termed an "omitted decompression stop." The consensus today is that there's little benefit to returning for a "do over." By then, whatever bubble formation has occurred, if any, won't be rectified by going back a second time. The idea is to not omit the stop in the first place.
Your question demonstrates that buddy separation can be a very significant issue, aside from the problems incurred by diving alone. If buddies must return to the surface to reunite, it may increase their decompression risk; so the answer is to make sure it doesn't happen by remaining attentive to each other throughout the dive.

Q:A reader whose name was lost due to a corrupted e-mail had a follow-up question about a question from a previous column. In it I described a concern over making a short "bounce" dive, and how this might increase one's risk of decompression illness. "Could you expound on this? What exactly did you mean by ‘… deep dive soon after surfacing could compress these bubbles to a point where they might be able to pass through the lung's "bubble net"?' Also, you refer to ‘bubbles that have already grown.' Does that refer to microbubbles? I thought the whole idea of making slow ascents and safety stops was to avoid bubbles from forming in the first place. Or are you saying that most divers (if not all divers) do end up with some amount of bubbles in their tissues after a dive?"
A:Let me take your questions in reverse order. Years of research on recreational divers have clearly shown that, though not on all dives, it's not uncommon for asymptomatic or "silent" bubbles to form even after dive profiles that are well within the so-called no-decompression limits. However, the relationship of these bubbles to decompression illness is unclear as sometimes people get DCI even when they have not developed silent bubbles.
The purpose of a safety stop is to help reduce the level of nitrogen in our tissues slowly which, hopefully, will reduce the likelihood of bubble development. However, a safety stop doesn't necessarily preclude development of silent bubbles, or resolve those that might have formed.
My reference to the "bubbles that have already grown" did, indeed, refer to silent bubbles. I also explained how the lungs, under normal circumstances, act as "bubble traps" to remove them from circulation. However, there may be mechanisms whereby the bubbles get past the lungs, and one of the mechanisms is through the bounce dive phenomenon discussed in the column in question (August 2009). There is also another theory proposed by some that, when bubbles in the capillary beds build to excessive levels, vessels can open up and allow some blood to bypass the lungs altogether (a process know as shunting), allowing them into arterial circulation. Keep in mind that this is all speculative, but one thing is certain: There are circumstances, by whatever means, in which bubbles can bypass the lungs.
Finally, there's another bubble bypass mechanism that's not speculative, as it's been demonstrated in a number of studies. This involves the "hole in the heart" phenomenon or patent foramen ovale (PFO). Here, rather than through the lungs, bubbles are transferred from the right (venous) to the left (arterial) side of the heart via this small opening. Space precludes my getting into more detail, but we will be running a feature article on PFO sometime next year. Stay tuned.
Q:Diver Jed Bedy asks about the implications of diving for those with a very common disorder. "What is the reality of danger from acid reflux and diving? I was told that you could die if you have acid reflux active and descend. True or false? Also, what are the implications of esophageal varices bleeding? Does it mean you can never dive again? If you take beta blockers to lower blood pressure, you're out?"
A:Acid reflux or, more correctly, gastroesophageal reflux, is a backward flow of acid or food from the stomach into the esophagus. As every one knows who has experienced it, the symptoms include burning upper abdominal or chest pain, sour taste or food regurgitation. In divers this can happen, especially, when they're in the head-down position. Furthermore, symptoms can be exacerbated by drinking alcohol, smoking, an ulcer or hiatal hernia and certain medications such as aspirin or nonsteroidal anti-inflammatory drugs (NSAIDs). For divers, it can even happen as a result of a tight-fitting weight belt or wet suit.
In the case of occasional mild symptoms ("heartburn") the risks include the possibility of vomiting underwater, which can result in drowning. Also, aspirating food or acid into the lungs can be fatal. Those with reoccurring symptoms should see their physician. As to whether you can dive, that's a call that will have to be made by your doc, and I've seen it go both ways. So, it may not be an absolute contraindication, but it's certainly a significant medical condition that must be evaluated before starting or returning to diving. Advice from the Divers Alert Network, however, is pretty clear. They suggest unequivocally that individuals with significant reflux should not dive.
For those unfamiliar with the disorder, esophageal varices are extremely dilated submucosal veins in the lower esophagus. They are most often a consequence of a condition known as portal hypertension, commonly due to cirrhosis. The problem is that patients with esophageal varices have a strong tendency to develop serious bleeding. I've had no direct experience with any diver with this condition. Again, it's a call best made by your physician, but I'd bet most docs would advise against diving with this condition.
The medication used to treat varices, such as the beta blockers you mention, can cause their own problems. Specifically, beta blockers can reduce the heart's exercise capacity, thus affecting exercise tolerance. Any medication that restricts the heart's function during exercise puts one at an increased risk for loss of consciousness. While that may not be a life-threatening concern on the surface, underwater it could prove fatal.

Test your knowledge of the information featured
in this month's issue of Dive Training.

1. The human body experiences heat loss resulting from:
A. Radiation.
B. Conduction.
C. Convection.
D. Evaporation.
E. All of the above.
2. Shivering causes:
A. An increase in metabolic heat
B. A decrease in metabolic
heat production.
C. Fatigue.
D. Dehydration.
3. In humans, the area of greatest heat loss occurs at the:
A. Base of the neck.
B. Armpits.
C. Groin.
D. Head.
E. All of the above.
4. Research indicates that
hypothermia can increase the
risk of decompression sickness.
A. True
B. False
5. The primary effect that the moon has on the ocean is:
A. Seasonal monsoons.
B. The Equatorial Gyre.
C. The creation of tides.
D. Spawning cycles.
6. Over the roughly 30-day lunar
cycle, the Earth, sun and moon progress through a period when the three bodies align, resulting in the highest tides, called:
A. Lunar tides.
B. Spring tides.
C. Near tides.
D. Neap tides
7. Changing ocean tides affect the flow of rivers.
A. True
B. False
8. Lizardfishes are sometimes
collectively referred to as:
A. Jokers.
B. Vacuum cleaners.
C. Bullets.
D. Grinners.
9. All flatheads are Indo-Pacific species that occur in:
A. Brackish water.
B. Saltwater.
C. Both A and B are correct.
10. Frogfishes are known to propel themselves by:
A. Forcing jets of water through
their gill openings.
B. "Walking" on their pectoral
and pelvic fins.
C. Both A and B are correct.
Answers Below...
Answers: 1. E 2. A 3. E 4. A 5. C 6. B 7. A 8. D 9. C 10. C