I've been enjoying these replies!
I'll fill in a little more about my contingencies on that test.
1.The hard bottom was my go to in case of trouble. (
@RayfromTX your joke is my dive mantra. Majority of my diving is shore or cave. Both your can remove fins and walk home)
2. I was carrying my camera about 2lbs negative which can be easily dropped (easily in theory, I'd hate to lose it).
3. 5lbs lead weigh could have been dropped.
4. My dsmb and 250ft reel would be an option. Regarding narcosis, it's significantly easier to deploy than manual dual strobe macro photography holding position in a solid current.
I've experienced significantly worse narcosis under heavy workload in deep cold blackwater diving back home in Canada (Where I originally learned to dive as a youngster, no bcd) doing valueless salvage for pleasure. The experience this was built on was learning to dive from mentors who considered around 320-340ft the limit for air and who dove near there extensively. I've put in a few hundred dives below 240 on air myself. Narcosis management I've never been taught formally, would like to. Reading everything I can online, particularly the gas density studies. My background involving deep air might derail the thread so I hesitated to mention it. Anyone have a stick? I'll bring the dead horse.
In way of update: I enjoyed the dive so much I left my camera behind, switched to lighter fins and did it again today!
With the 3lbs further ballast removed I was comfortable to 75ft and could still hold neutral quite a bit deeper, seems the extra ballast reduction make for significant comfort increases deeper as the wetsuit seems to reach crush depth and doesn't get much less buoyant. Not having the drag of camera and needing to hold against the current for pictures made a huge difference as well.
Held deco comfortably at 15ft @ 500psi (X2). Turns out I didn't miss the 3lbs.
I've not measured lung volume since a serious health issue 5-4 years ago. Use to freedive extensively and am rebuilding slowly. Lung capacity, particularly the "comfortable" range, is the decided factor in how much buoyancy we can compensate for internally. I'll test it out soon to run some hypothetical math.
Regarding getting positive on the surface if needing to call a dive: Dropping the 5lbs and (worse case) emptying the tanks would give me nice lift when combined with a safety sausage hobby horse to ride. I really like the idea of the snorkeling vest, because dropping lead for a stupid reason would be annoying. For a while I use to carry an aircraft emergency life vest with a co2 cartridge as a security blanket.
Streamlined diving, trim with equipment at the bare minimum is really enjoyable. Less drag has tangible results when dancing with the currents and contours.
The study in weight management as
@REVAN describes is satisfying.
Great discussion!
Cameron
P.s. It's nice to hear some others are out there enjoying streamlined diving. Giving me good ideas too.