| OK, just re-read your post and you want to try and avoid taking the 15, and just taking 3 sets of Dil Cylinders. If you are planning on doing 5-8 dives, then you're looking at at least one top off per cylinder, and maybe 2 top ups.
If we make some asumptions:
You start each dive with the dil at 200 bar, and you end the dive on 100 bar, that should provide sufficient contingency.
You could start with a Heliox dil, then your first top up will be the first time you introduce any N2 into the Dil, this will give the the max possible extension of the Helium while keeping the N2 as low as possible.
If you start with a 15/85 Heliox, then a 100bar top off will take this to about 18/40 Trimix, which is a little hot for 80m, but fine for 60-65m. |