Steve Straatsma

Steve Blue Hole diving in Cay Sal, Bahamas

Steve first started shooting underwater in 1973 with an old Brownie camera in a plastic housing in the springs in North Florida. He graduated to a Nikonos III and Sea & Sea strobes in 1978, and was encouraged to continue progressing by winning two categories in the Florida Skin Divers Association photo contest that same year.

Steve’s primary interest over the years has been photography in little-documented places, primarily deep cave sites, as no one else was doing this until Wes Skiles advanced the activity with multiple strobe cave photography, a technique which I promptly took up.

The Nikonos II was my weapon of choice as it would go deeper than any other Nikonos or housing (over 300 feet) and still function, using the superb Nikonos 15mm lense and either Sea & Sea or Ikelite strobes. Over the years Steve has dad photos published in Skin Diver, Sport Diver, Advanced Diver Mag, Readers’ Digest, NACD and NSS/CDS Journals, and numerous newspapers, books, and local magazine articles.

Steve converted to digital photography with Nikon/Aquatica/Ikelite equipment in 2004. “Digital is truely an incredible media…the possibilities are endless!”

You can see other pictures of Steve’s in various parts of Divingindepth.com. Steve has been a kind and gracious contributor to Divingindepth.com, and we want to thank him for that!





Cave Training

There are three levels of training courses you must take before being fully certified to cave dive. Once you complete your cavern course, the next steps are an intro to cave diving course, an apprentice cave diving course, and finally a full cave diving course. Each of these courses provides different levels of training and requires different prerequisites.

An intro to cave diving course is the second level in your cave training after completing a cavern course. In this course, you depart the daylight zones of a cavern and enter cave tunnels using linear penetration on the main lines in a cave system. This course refines your basic overhead environment skills, teaches you various emergency procedures within the cave, enhances your propulsion techniques, and builds your mindset to safely dive in a cave system. Penetrations into the cave are limited and at a conservative pace. The course continues to build your skill level but does not prepare you for all levels of cave diving.

Additional equipment required is a primary reel with at least 400 feet of line, at least three battery powered lights, one being a primary light and two backup lights, a tank with a dual orifice such as an H-valve, an additional regulator with a minimum five foot hose, and line markers. All of your standard cavern course gear is also required.

The intro to cave diving course is generally taught over a two-day period and requires at least five dives.

An apprentice cave diving course is the third level in your full cave diving certification after a cavern course and intro to cave course. Training emphasizes expanded dive planning skills through conducting dives, provides an introduction to jump and gap procedures and continual improvement of the procedures, skills, and emergency drills previously presented at the cavern and intro to cave courses.

Gear requirements are double cylinders with a manifold, a seven-foot hose one of your regulators, compass, line arrows, and at least two secondary reels for gaps and jumps.

The apprentice cave diving course is generally taught over a two-day period and requires at least four dives.

A full cave diving course if the final training course in your pursuit of a full cave diver certification. This course exposes you to more sophisticated cave diving scenarios, expands upon the skills you learned in previous courses, builds your navigational skills, and introduces cave surveys. A primary focus of the course is to show you the proper procedures for completing traverses and circuits. When conducting these dives, you’re responsible for all dive planning, gas management, and the execution of the dive.

There are no additional gear requirements than that of the apprentice cave diving course.

The full cave diving course is generally taught over a four-day period and requires at least eight dives.

Hedging the Bet Against Oxygen Toxicity

by Tim Peever

Some Physiological Factors and Possible Controls of Oxygen Toxicity

Oxygen Toxicity manifests itself in two ways, pulmonary oxygen toxicity and central nervous system (CNS) oxygen toxicity. Of these, CNS oxygen toxicity is the most serious concern to scuba divers.

Pulmonary oxygen toxicity involves attack on the gas transfer membranes in the lungs by oxygen free radicals from long-term exposure to high partial pressures of oxygen. The time involved to manifest symptoms of pulmonary oxygen toxicity is many hours and would not affect a diver except in cases of recompression therapy.

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Housing Basics

To get a camera to go underwater, take pictures, and get it back safely to the surface and in one piece without flooding it, you need to protect it from the elements somehow. This is where the underwater housing and the amphibious camera come in. Housings and amphibious cameras approach the same problem from different directions. The housing surrounds and encloses your camera to protect it, while the amphibious camera itself is sealed from the elements.

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European Sea Floor Observatory Network (ESONET)

Looking to be completed by 2011, the European Sea Floor Observatory Network (ESONET) is being developed by international research institutions who are collaboratively spending roughly 300 million dollars to build it. There are 11 primary European partners listed in the main document (http://www.oceanlab.abdn.ac.uk/esonet/ESONET_fullrep.pdf).

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