[apneaboy]

Hi Cal. I dive in a 3mm Elios suit in summer and a 5mm in winter (and winter winter with an extra 1.5mm vest). 15 degrees c at the bottom... mmmm toasty :-)

In fresh water i use 1.25kg for the 3mm
In fresh water i use 2.5kg for the 5mm

I can comfortably breath on the surface without moving and i am still positive, i am neutral between 12-14 metres and start sinking about 20-25m for both suits. Being negative any earlier makes the way up a long way up and any problems your buddy has a harder job especially if you let out air. Vov is right it is a personal decision and your size and muscle density, fat percentage etc will probably make you different from me.

For scuba where the dive is mainly spent at the coldest temp i needed a much thicker suit and a lot more weight because i need to be neutral shallower but with freediving you can warm back up on the surface. For freediving the thinner the suit you can get away with and be comfy still the better for many reasons.

Vov i dont quite understand about this hose situation you have going on? Are you adding air from a compressed air source to a wetsuit on the way down and letting the seals keep the air in?

One option would be rather than add buoyancy at the bottom is to have a weight at the surface attached to a line to take you down initially then let go of it so that on the way up you will still have guarenteed buoyancy rather than air in your suit which can be lost unless i've misunderstood.