This roadside gem situated in Islamorada just down the road from Bud & Mary’s Marina tells the story of mankind’s quest to explore, understand and venture under the sea. It contains hundreds of artifacts including one of the largest collections of historical diving helmets from around the globe.

The museum chronicles the history of diving from more than 4,000 years of human history – from breath-hold divers and early diving machines to the development of the diving helmet and the change to swim diving with early SCUBA. There are also exhibits to explore about sports diving, underwater photography, treasure diving, and marine biology.

A special exhibit about commercial and military diving displays how advances in these fields have contributed to the advancement and popularity of modern recreational diving. You can also see diving armor and an early collapsible decompression chamber.

The Museum is located at MM83 Bayside, and is open from 10 am to 5 pm every day of the year except Thanksgiving, Christmas Day, and New Year’s Day. Admission is only $10 with this coupon http://www.divingmuseum.org/visit-our-museum/admission-prices/.  It is a fascinating attraction for divers of all ages and well worth the time to explore. For more information, go to http://www.divingmuseum.org.

Some ADA members have been diving so long that I heard someone say we should change our name to the “Aged Divers Association.”  Diving technology has come very far from the days that we dove with only two simple instruments, a depth gauge and an air pressure gauge, to assist in calculating bottom times, rate of ascent and surface intervals.

The first generation of dive computers were widely considered “extra” pieces of equipment that were nice to have, but not absolutely necessary, because they used only dive time and maximum depth to perform the same calculations we learned with dive tables. Now a dive computer is an essential part of any diver’s gear.  Ranging in price from a couple of hundred to thousands of dollars, equipment manufacturers now offer computers with an ever-widening variety of features to select from which all certified divers should consider in making their purchasing decisions.

The primary purpose of a dive computer is to minimize the risk of decompression sickness from any one or a combination of factors including diving too long, diving too deep, diving with insufficient surface interval, ascending too quickly, and otherwise failing to deal with the loading of nitrogen into your body as a result of breathing compressed air at depth.  Dive computers provide much important data for the diver, including current and maximum depth, water temperature, bottom time, ascent rate, safety stop depths, and surface time.  In the “no decompression” dive mode, a computer will count down the dive time remaining before decompression is necessary.  Bar graphs on computers display easy to read nitrogen loading calculations using both compressed air and nitrox mixtures based on single or repetitive dive profiles, time before the diver can safely fly, and other information.

Modern dive computers feature air integration capability, which uses tank pressure and breathing rate in conjunction with the actual dive profile to calculate the time remaining on a dive.  Such air integration systems can be hose-fed, using the console-type computer, or wrist-mounted, using a transmitter connected to the regulator first stage to communicate with the computer.  Some hoseless systems even allow a diver to monitor his or her buddy’s remaining air and dive profile.

Some computers use more conservative algorithms than others, and divers should research those differences before investing in a computer, so the computer matches the user’s diving style.  Other features that are important to research include the display types: dot matrix, organic light-emitting diode (“OLED”), and liquid crystal display (“LCD).  For older divers, the size and readability of displays may be the most important feature of a dive computer, as there is no need for more “bells and whistles” if we cannot see them while under water.

We have come a long way from manually calculating our no-decompression limits using a plastic card containing intersecting lines of maximum depth, bottom time, and surface intervals.  A good dive computer can go a long way toward preventing decompression sickness, but common sense and good training remain as our best tools to maintain the long safety record of the Active Divers Association.

See you on the bottom.

Long before cavern diving became a recreational diving certification area and cave diving was recognized as a sophisticated technical diving specialty, my first dive buddy, Paul Glass, and I enjoyed exploring the springs and sinkholes of north Florida.  My best friend Paul owned the only dive shop in Lexington, Kentucky, where I lived in the Seventies, and he was a dive instructor (first with Scuba Schools International, and later with PADI).  I made several trips with Paul to the Keys to assist him with the final check-out dives for classes of his students seeking Open Water Certification.  On the way back to Kentucky we would stop at various sites in the northern part of Florida for refreshing fresh water dives in Ginnie Springs, Orange Grove Sink, and other scenic areas.  The water was so crystal clear in those sinks that you could see leaves floating on the top from a depth of more than 100 feet.

Some of the diving was in caverns.  A cavern is a cave-like structure in which the light from the entrance is always perceptible, so divers can find their way out without the need for safety lines stretched from the entrance along the route of the dive, which can be followed back out.  On one such dive I went into a room of the cavern through a large opening, and then tried to exit the room through a smaller opening near the roof of the room. That is when my trouble began.

Do you know why they taught us to turn on our air by opening the valve on the tank all the way, and then closing it a half turn?  I found out as I tried to wriggle my way through the small cavern opening and rubbed the knob on my tank enough to turn off the air, right at the same time I wedged myself into the crevice so tightly that I could not get out.  I had only opened the tank valve about one turn and it closed as the knob rubbed along the roof of the cavern.

At first when I tried to inhale and got no air, I thought it was a malfunction with my second stage.  I found my octopus and tried to get a breath from it, but there was no air there either. I began to get a little worried.  I could see some of our recently-certified students in the main part of the cavern I was trying to reach when I got stuck, so I used my flashlight to get the attention of one of them, giving him the “out-of-air” signal.  Luckily he saw me, came right to me and began to buddy-breathe with me, just like he had been trained.

By that time, my buddy Paul realized that I was stuck and he pulled me back out the way I had come, and turned my air back on. I guess that the situation had made me nervous. Paul later said that he could see beads of sweat on my forehead, inside my mask when he dislodged me from the cavern.

Back on the boat I tried to act as relaxed as I could. When the student who buddy-breathed with me got back in the boat he said, “So why were you testing me with that buddy-breathing exercise again? Didn’t I get certified yesterday?”  I thanked him for helping me, assured him that he was certified and was really glad that he had learned his lessons well. That was when I learned why it is important to open the tank valve all the way and to keep out of small openings in caverns