Going from AL100, salt, no wet suit ---> HP100, fresh, 5mm... advice please.

[boulderjohn]

These dives will include some work with Pete 'NetDoc' on trim/ buoyancy over a few days.

I am sure Pete will do a great job with you.

 

[spectrum]

In you opinion would someone be able to 'swim up' a somewhat empty HP100, with a compressed 5mm wet suit, if my BC failed?

My best answer is that I would think so.

Assuming you are correctly weighted as described what is it that you need to swim to the surface?
1) 100 CF of air weighs 8 pounds. 1 pound or so is factored into being neutral so an incident at the start of the dive offers 7 pounds of unbalanced negative buoyancy.
2) The wetsuit will be somewhat compressed, assuming 50% of the 10 pounds I have observed it is 5 pounds of unbalanced negative buoyancy.

Combined, that is 12 pounds you would need to swim up and it will diminish some as you ascend. With good fins and technique that sounds manageable but I'll admit I have never done an objective test. It could be an interesting exercise. If you are breathing heavy with full lungs that alone will provide some lift to help. If it occurs latter in the dive as you suggest the challenge will be proportionally less.

Pete