THE COVERS Articles & Editorials JULY 1999 • Volume 9 Number 7 
  
By keith ibsen		 Wall diving holds differing attractions for different divers. Some enjoy the thrill of being suspended over a seemingly bottomless ocean. Other divers are intrigued by the cliff dwellers that inhabit every ledge, overhang, nook and cranny along the face of the wall. No matter what it is that drives you "over the edge", wall diving presents special challenges. Author Lynn Laymon describes wall diving's intricacies - and how you can be a better wall diver - in his feature article "Vertical Awareness: The Art of Wall Diving." 
FEATURES
22 Vertical Awareness: The Art of Wall Diving
One of the greatest thrills of diving is found where the gently sloping shorelines of the world's landmasses turn vertical and plummet to the depths of the oceans. In diving circles these drop-offs are known as The Wall. Wall diving is fun and easy but it does present several challenges. Find out how to use your diving skills to adapt to a vertical underwater world. 		By Lynn Laymon
30 The Great Algae Mystery: Zooxanthellae
Zooxanthellae are the answer to one of the greatest scientific mysteries of the twentieth century. If you have ever been diving around a coral reef you have been in close proximity to more zooxanthellae than you could possibly count at one time, probably more than you could count in a lifetime. Zooxanthellae are crucial to the very existence of all coral reefs and to all animals that depend upon coral reef communities. Still don't know what the heck zooxanthellae are? Well, if you don't know, don't feel too bad. You are not alone. Most non-scientists wouldn't have a clue. 		By Marty Snyderman
38 Are You a Good Diver? Check Your Attitude, Awareness and Actions
What is a "good" diver; how can you tell if you are one - and most importantly - if you determine you're not, how do you become one? The author invites us to take a look at what we've learned - and what our limitations are - as we strive to become better, safer divers. 		By Linda Lee Walden
COMMENTARY
8 Guest Editorial: A Family Thing By Marty Bass
10 Buddy Lines: Checklist Check-Up
16 Diving Notes and News: From Promotion to Protection: Ocean Fest Organizers Seek Marine Sanctuary Status and other news from the diving industry By Alison Courtney
96 No Dumb Questions: "I Can't Clear My Ears" Tips that will help open your eustachian tubes By Alex Brylske
DIVE EXPLORATION
66 Dive Geo: Palau Micronesia's Emerald Isles Above water, Palau exudes tropical island beauty at its finest. Underwater it's as rich and diverse with life as just about anywhere on the globe. By Jesse Cancelmo
76 Dive Traveler: Your Ship Is In Cruise Ship Diving and Snorkeling: Cruising and diving can be a good vacation combination. By W. Lynn Seldon Jr.
80 Passport: Dive travel incentives around the globe
Compiled by Cathryn Castle
EVERY MONTH
45 Scuba Skills: Using a Dive Float and Flag A dive flag is more than just a T-shirt logo. Find out how to use a flag and float safely. By Linda Lee Walden
49 Always Learning: More Bang for the Energy Buck: Do Less, Accomplish More. How to eliminate "scuba-scurrying" By Mark Twombly
53 Imaging: Automatic Exposure Photography Ready, Aim, Fire! An automatic exposure camera system can allow you to spend less time adjusting the camera and more time concentrating on your subject. By Dave Albrecht
59 Dive Instructor Tips: Teaching Coral Reef Ecology. Coral reefs are best understood by students not as amalgamations of individual organisms, but as one "superorganism." By Alex Brylske
74 Diving Through the Decades: The 1940s In this ongoing series, we recall a decade every month - the events, personalities, inventions, and trends that made diving what it is today. By Eric Hanauer
81 What About: Eyeball to Eyeball With an Alligator A Thrill-Seeker's Dream Turned Nightmare. When "up-close-and-personal" gets "too-close-for-comfort" By Jan Neal
85 Dive Medicine: Protection from the Sun: How to handle solar radiation without getting burned By Paul S. Auerbach, M.D.
92 Smithsonian Reports: Smithsonian scientists report on the National Zoological Park By Michael Lang, edited by Alex Brylske
94 Dive Shop: New Equipment Showcase
Compiled by Cathryn Castle
101 What's That?: Coral "Anemones" Not Exactly Anemones. The difference between corals and anemones and why it's hard to tell By Dee Scarr
108 Classifieds
113 Dive Training Quiz: Test your knowledge of the information in this month's issue
114 Final Check: What It Looks Like... When You Maintain A Safety Margin. The mark of safety - or stupidity - is on your pressure gauge By Lynn Laymon