Mark E. Derrick

mark@n2diving.net

I’ve been an IANTD technical diving instructor for many years and have been a certified SCUBA diver since the early 1970s. Originally from North Alabama, I earned my first rebreather instructor rating in the late 1990s.

After retiring from the information technology sector in 2000, I moved to Florida and focused full-time on technical diving instruction. Now based in Pompano Beach, Florida, I continue to teach rebreathers, including the Poseidon Seven+ CCR on staff for Dive Gear Express.

Dive Gear Express operates as a streamlined retail e-commerce platform serving experienced divers. Equipment configuration, fulfillment, and customer support follow disciplined, system-driven processes with consistently applied documented standards that emphasize repeatably correct outcomes. Similar documented standards for correct equipment configuration, practical standards-based training, and operational reliability are reflected in my closed-circuit rebreather (CCR) instruction.

This site is a personal collection of technical articles and reference pages that I have authored on subjects that interest me; some of my favorites are listed here. It is not trying to sell anything or persuade you to do anything. My most recent article, Porsche Taycan Charging Explained, grew out of a personal exploration of the topic.

• Porsche Taycan Charging Explained
• How E-Commerce Works in the US
• Transitioning to Rebreather Diving
• Oxygen Sensor Handling for Divers
• Sofnolime CO₂ Absorbent for Rebreathers
• Witness to a Rebreather Fatality
• Poseidon Se7en+ FAQ
• Calculating SCUBA Cylinder Capacities
• Southeast Florida Dive Resources