What Does It Mean?

A PROFESSOR OF EMERGENCY MEDICINE and researcher at the University of Maryland School of Medicine, Stephen Thom holds medical and doctorate degrees from the University of Rochester. He previously led various clinical programs, including hyperbaric and emergency medicine, and a research lab at the University of Pennsylvania. What is your academic background? My medical specialty […]

A Hole in My Heart

I HAVE BEEN A CERTIFIED DIVER since 1986 and have logged hundreds of recreational and technical dives. Since 2014 I have primarily been doing technical rebreather diving with a close group of experienced rebreather divers from Northern California. During the summer of 2019, our group visited Lake Huron’s Thunder Bay National Marine Sanctuary in Michigan […]

Not Only for Diving

WHILE DAN’S SUITE OF EDUCATIONAL PROGRAMS focus primarily on diving, graduates of the courses can apply the skills and knowledge they learned to many circumstances outside the aquatic realm. My wife and I were driving home from a weekend getaway to Myrtle Beach, South Carolina, heading northbound on Interstate 95. As expected, I-95 was moderately […]

Building Better Balance

DIVING TAKES PLACE in an environment that is dynamic both in and out of the water. Challenging and changing situations can happen even while traveling to a dive site. Balance exercises can help improve your ability to maintain or regain stability on a rocking boat. Wearing scuba gear changes your weight distribution and center of […]

Iceland

It’s not every day you can witness the inner workings of our planet by taking a live look under the hood at the engine of creation. Some scientists claim that life on Earth began from hydrothermal vents in the ocean’s abyssal reaches. That realm is much deeper than where I float now, but otherwise it’s […]

Low-Visibility Diving

WEATHER, SILTY SEDIMENT, time of day, or water movement are just a few natural factors among the range of possible causes that can influence the visibility at your dive site. Low-visibility diving can be quite enjoyable, but it depends on the circumstances and your comfort level. Why do people dive in low-visibility environments? Some divers, […]

Underwater Smartphone Photography

LIKE ANOTHER UNIVERSE, the underwater world is full of whimsical inhabitants, sinuous sharks, and huge mammals that have always fascinated people and probably always will. As a photographer, you enter completely new territory when you begin shooting underwater and learning how to adapt to the conditions of the aquatic world. Lighting subjects underwater differs significantly […]

Laryngospasm and Anxiety

Q: During dive training in the pool, I couldn’t breathe after clearing my mask with my regulator in my mouth. After surfacing, I took six to eight wheezing breaths and then could breathe normally again. It’s possible I inhaled water during the exercise, but my instructor and I could not recall when or how that would have […]

Scuba Cylinder Rundown

The 11-liter aluminum 80, aptly named for its 11-liter internal volume and 80-cubic-foot capacity when filled to its 200 bar/3,000 PSI rated pressure, is by far the most common cylinder. Just because it is the most common, however, may not mean it is the right one for you. Cylinders come in a wide variety of […]

High-Pressure Hoses

PEOPLE WHO HAVE FILLED scuba cylinders, refilled oxygen cylinders, or boosted a gas mix are familiar with using flexible hoses. Some hoses are covered with a durable rubber or thermoplastic jacket, while others appear even sturdier with a braided stainless-steel mesh on the outside. Correctly specified hoses are rated to pressures of up to 6,000 […]

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