Lucy's Diver
Contributor
It's ~210ft to the sand on the San Francisco Maru if I remember correctly.
While I'm not generally a big promoter of deep air, if you're ever going to do it, Truk would be the place -- 85ºF water, great visibility, little to no current, etc. Doing it in cold dark water off the northeast coast isn't something I would consider to be a wonderful idea.
186 feet is the max depth of the San Fran in the rock bottom of the forward cargo hold, the one with all the 800 pound bombs leaning inward ready to fall out of their rotting crates.
The deck with the mini-tanks is 165 feet.
8 minutes between these two points left me with minor deco on 24% EAN, which did yield a 1.6 PPO at max depth.
Things are deep enough in Truk that the operators usually run 30% (or so) EAN. The one I was with leaned it down to 24% for the San Fran and had staff stage themselves thoughout the water column, this was coordinated with client splash times to keep fresh staff with new tanks at the right places, they also staged tanks along the mooring line.
I did that on a steel 104 and my wife an AL80. In warm, clear, no current water with that much support I had no issue with the depth risks.
Also, there are very few real Navy Master Divers out there. There have been something like 350 in the entire history of the Navy. They tend to be career Navy and one teaching recreational scuba would be an anomoly.