Special tech episode of Pod Diver Radio, host Joe Cocozza checks in live from Beneath the Sea 2015 with SubGravity president and dedicated cave diver Josh Thornton for a deep dive into modern CCR gear. Josh shares how a childhood cenote dive in Mexico pulled him into cave diving—and how that passion now drives SubGravity's design philosophy. Together, they unpack the Hammerhead closed circuit rebreather, including: The online "Build a Rebreather" (BART) configurator that lets you spec your Hammerhead from can size to materials The removable O₂ cell cartridge pre-wired for up to four sensors, making swaps, drying and inspection easy Click-lock bayonet hose fittings that simplify setup, teardown and mushroom-valve checks—no threads, no hassle Then they turn to the H3 dive computer—a compact OLED unit developed with the Austrian military—covering: Full support for air, nitrox, trimix and CCR so you don't outgrow your computer NFC (near-field communication) logging straight to your phone for instant dive downloads and sharing The roadmap for wireless cylinder pressure and future wireless PO₂ monitoring, all enabled via firmware updates on the same unit If you're a CCR diver, a rebreather-curious OC tech diver, or a cave diver looking for robust electronics and modular life support, this Hammerhead + H3 breakdown is packed with practical, gear-nerd detail.

1. Post beneath the Sea. BTS 2007 post-mortem.2. D.A.N. Tech Time with Richard Vann PhD. 3. Deep Cave Cave exploration interview with Brett Hemphill

This special archive episode of Pod Diver Radio revisits one of our most memorable conversations — a deep technical sit-down with legendary cave explorer Brett Hemphill, recorded years before he later lost his life on a deep cave exploration dive. Brett walks us through the audacious project to connect Florida's Weeki Wachee Springs and Twin Dees cave systems, in what became the deepest underwater cave connection in the U.S. at roughly 330 feet. Joe opens the show recapping their earlier interview on Weeki Wachee, then Brett picks up the story: why Weeki's violent outflow (160–200 cubic feet per second) makes the "coffee-table–sized" 170-foot entrance almost impossible except in extreme drought, and how those same droughts turned nearby Twin Dees into a dead mud hole… until the rains came back and the spring came alive again. From there, Brett lays out the Twin Dees side of the expedition in classic detail: Dropping into a tiny 30-foot pond and squeezing through a "Superman" chimney starting at 15 feet Reaching a small room at 40 feet where the team built a habitat to stage and don gear Pushing through tight passage to about 1,300 feet before the cave opens up Entering "Middle Earth", a massive underwater chamber "three-quarters the size of the hall at Beneath the Sea" Following "the Tunnel", a passage leveling off around 300 feet on the way toward Weeki Wachee Brett then tells the story of the breakthrough: finding the monitoring well at ~6,300 feet back, 320 feet deep; realizing the connection had to be close; and finally seeing their old Weeki Wachee line appear out of the darkness only 30 feet past where his reel ran out. You'll hear how normally reserved Dr. Andrew Pitkin starts yelling through the helium — the moment they know Twin Dees and Weeki Wachee are one system, 8,000 feet back at 330 feet deep. We also dig into: The brutal logistics (even staging bottles is a 6-hour dive) Why these projects are impossible without a committed support team Sponsors and gear that made it possible (scooters, lights, CCR, reels) How to watch Brett & Andrew's high-def "Barrel and Loop" video section of Twin Dees Why Brett believed there is still unexplored cave and real exploration left in Florida This episode is both a technical masterclass in extreme cave exploration and a tribute to a diver whose work, humility, and curiosity inspired an entire generation of cave and spring divers — from mixed-gas explorers to freedivers drawn to Florida's clear, powerful springs.

PD157: EDGE-HOG Dive Gear Review. Interview with Jack Schmidt, Ops Manager for Edge Dive Gear.

PD156: Diving the B-29 Wreck in Lake Mead. Interview with Joel Silverstein of Tech Diving Ltd about diving the USAF B-29 Superfortress Bomber in Lake Mead. For more info about diving this historic wreck, contact Joel at TDL www.divetheb29.com

PD155: SCUBAPRO 2015 Gear Update.Audio Interview at BTS 2015 with Brad Lally, Product Director at Scubapro. We discuss, Scubapro's new cold water piston regulator, Trufit dive masks, Sidemount BCs and biometrics for scuba diving.

PD154: Dr. Neal Pollock at DAN discusses the issues surrounding aging and technical diving. Dr. Pollock is the Research Director at Divers Alert Network. Also, a Senior Research Associate at the Center for Hyperbaric Medicine at Duke University Medical Center. Also, he is a Board member of the American Academy of Underwater Sciences Foundation.

The 2015 Dive Rite demo of its full line of Recreational and Technical gear at Dutch Springs Quarry (75 miles from New York City). Divers got to try out: high power dive lights, sidemount and the Opt2ma Rebreather. We talked the divers about there experiences.

In this deep‐dive episode of Pod Diver Radio, host Joe Cocozza sits down at BTS 2015 with Dr Simon Mitchell (University of Auckland anesthesiologist, technical diver, and DAN Rolex Diver of the Year) to dissect his landmark rebreather prebreathe study. Mitchell walks us through the experimental design used with CCR divers on Inspiration units: Three loop conditions — normal scrubber, no scrubber, and a partial scrubber bypass (missing spacer O-ring) Blinded subjects instructed to perform a standard 5-minute prebreathe exactly as on a dive boat Termination criteria based on self-recognized CO₂ toxicity symptoms He then breaks down the results and implications for real-world CCR operations: 25% of divers failed to detect complete scrubber absence during prebreathe 90% failed to detect a partial scrubber failure, despite measured inspired CO₂ ≈ 20 mmHg All divers showed objective hypercapnic responses (increased ventilation, visible distress), but many did not recognize or report symptoms—highlighting how CO₂ narcosis itself impairs judgment Mitchell explains why the traditional 5-minute prebreathe cannot be relied on as a CO₂ scrubber integrity test, why partial failures are especially insidious (tolerable at rest, dangerous under workload), and how this should change the way tech divers think about: Scrubber packing discipline and O-ring checks Checklist-driven CCR assembly The emerging role—and limitations—of CO₂ sensors in rebreather loops Risk management for deep, high-workload CCR dives If you dive a closed-circuit rebreather, teach CCR, or write SOPs for tech operations, this episode is a must-listen, grounded in peer-reviewed data from Diving and Hyperbaric Medicine (March 2015) and explained by one of the leading voices in diving science.

PD151: DIVE RITE Equipment Update 2015 Jared Hires reviews new equipment for 2015. Including The LX20, a compact, handheld primary light, And..The HunterPac BCD; which combines features of technical and recreational BCD for Spear fishermen and/or Underwater Photographers.