Gag Straps and CCRs Are Mouthpiece Retaining Straps (MRS)—sometimes called gag straps—a good idea?For recreational rebreather divers, the answer is likely no. More evidence could change my opinion here, but at present, any recommendation for MRS use is weak. This topic was discussed at Rebreather Forum 4 (RF4), where [...]
Bonaire Tek Week 2025 I attended the 2025 Bonaire Tek Week at Buddy Dive Resort. It was my first time in Bonaire. I taught a class for a few days and did some fun diving the other days. Here is a synopsis of what to expect when traveling to [...]
CCR Calibration This article is a refresher for certified CCR divers. This does not replace manufacturer recommendations, formal training, or time with an instructor. If you're confused about any of these aspects, contact your instructor and schedule a refresher. This article is specific to the O2tima CM unit. Other units are different. When [...]
CO₂ Scrubber Use in the O₂ptima CM CCR Disclaimer: This article is a refresher for certified CCR divers. It does not replace manufacturer recommendations, formal training, or time with an instructor. If you are unclear on any points here, contact your instructor and schedule a refresher. This information is specific to the O₂ptima CM [...]
Oriskany Trip My first trip to the "Great Carrier Reef" was 2014. I've been there a few times since, but the most recent trip was with a few friends in 2025. The Oriskany is an awesome dive site, especially for technical divers with wreck penetration [...]
Is CCR for Me? Disclaimer: I make a living selling rebreathers and rebreather training. Therefore, I have a vested interest in getting people to take classes and buy units. However, I routinely tell people that a CCR isn't a good option - because it isn't for them. I put this text together to [...]
CCR Setpoints A crucial concept for CCR divers is the relationship between loop volume, loop PO2, and buoyancy. All three work together. Our loop is what we’re breathing and is an airspace. This airspace effects our buoyancy control. As we descend, the loop volume decreases. We need to add [...]
Scuba O-rings O-rings are small but essential parts of scuba diving gear, sealing connections in regulators, hoses, tank valves, and other equipment. A damaged or missing O-ring can cause leaks or equipment failure, which is why having the right replacements on hand is crucial for solving problems in the field. This guide [...]
Common Scuba Hose Lengths Choosing the right hose lengths for your scuba setup is essential for underwater comfort, safety, and efficiency. Whether you're diving recreationally with a single tank, exploring caves in a sidemount configuration, or using a rebreather, the correct hose lengths can make a big difference in streamlining your gear and [...]
Petrel 3 Warranty In September 2024 Shearwater released a bulletin on their Petrel 3 computers. This bulletin identified a problem with the computers, open circuit, and closed circuit. The problem can cause a failure, during a dive, which resets and disables the computer. They immediately released this bulletin and, [...]
