| you're not going to find a preprinted one for 50% and 75% as both of those gases would be considered a deco gas. Preprinted ones usually contain a backgas and a deco gas. Using that combination your max bottom depth would be 21m and you would have to be carrying quite large tanks to get into deco. something like twin 26's in fact. You'd hit CNS problems before deco problems.
On top of that problem, 75% is not really a standard gas in anyone's book so that would be a nonstarter anyway.
If you're talking about AIR, and 50% and 75% this doesn't make a lot of sense either. By the point in the ascent where you would be swapping onto ther 75% you're into the intermediate stops and might as well boogie on up to the shallow stops and push the gradient. You're not really getting that much benefit from the 75% overt he 50% (depending on the model you choose I guess). It knocks a few minutes off a 30 minute dive to 50 metres, but you have had to carry an extra stage for the hassle. You run into backgas limitation problems anyway, so there's no real benefit in carrying the second stage.
If you need this for some sort of bizarre " how to choose a wierd combination of gas mixes presentation" then just burn your own using the software you state you are using. Just about every soft app out there worth it's salt will allow you to do this. |