Basic Scuba Course to Forty Fathoms Deep: DAN Physiology, St. Lawrence Wrecks & Diving Legend "Hal Watts"

On this episode of Pod Diver Radio, host Joe Cocozza and Rescue Diver Rachel kick things off with a chilly New Jersey reality check: teaching a PADI Open Water Diver class in a just-opened backyard pool on a 48°F rainy day. From gear selection at Divers Two to managing nervous new students (including one worried about things that might eat her in the water), Joe walks through how he introduces masks, fins and snorkels, pool skills, and the path from first bubbles to future wreck and cave dives. In segment two, Joe heads to Beneath the Sea for a sit-down with Donna from Divers Alert Network (DAN), a diving physiologist and Women Divers Hall of Fame inductee. They dive into hyperbaric physiology, including DAN's long-running flying after diving studies at the Duke chamber, how Doppler and echocardiography are used to detect bubbles, what current research says about women and diving, and new guidelines for diabetic divers and technical divers whose downloadable dive computers are feeding DAN's next generation of safety data. Next, tech diver, journalist and inspiration diver Rosemary Lund joins Joe to talk about diving the St. Lawrence Seaway / Thousand Islands. She paints a vivid picture of warm, clear freshwater wrecks like the Gaskin and Keystorm—intact hulls, timber and decking preserved for decades, 60-foot visibility thanks to zebra mussels, and long multi-level profiles that let you tour deep and shallow sections in a single dive. Rosemary also shares practical notes on rebreather travel and logistics for UK and international divers heading to North America. Finally, Joe sits down with deep-diving legend Hal Watts, founder of PSAI (Professional Scuba Association International) and owner of Forty Fathom Grotto in Ocala, Florida. Hal recalls the early days of "deep air" before anyone called it technical diving, talks about narcosis management, why he created an extended-range training agency, how performance-based depth limits work on PSAI cards, and what today's aspiring tech divers should look for in an instructor and training site. From freezing pool sessions with brand-new students to 240-foot sinkholes and North American wrecks, this episode spans the full arc of recreational to technical diving—with physiology, history, and a few good war stories along the way.