Technical diving for Insane and Hardcore Scuba Diver only?

You have seen photos of these scuba divers. You may even have seen them go to your local dive site. They have a lot of shells, most ...

Comparison of STANDARD HORIZON HX851 with NAUTILUS Lifeline DIVER

I was one of the early pre-orders of NAUTILUS LIFELINE DIVER VHF (with GPS and DSC capabilities). I am an electrical engineer by pro...