73diver
Contributor
I dive sidemount off a boat. My preference is to kit up and walk off the back of the boat. With two Worthington LP85's and ballast, I'm supporting about 80#. I noticed that there is an FX71DVB cylinder made by Faber and marked BSE71 rated at 3442PSI. The catalog lists the FX71 as 25# while the LP85 is listed as 37#. The buoyancy empty and full compares equally. Of course there is less air in the 71's. However, it would appear that I could take 22# off my back with a tank change. It is approximately the same switching to FX80 (i.e. 20#). This seems too good to be true, I'm wondering if I have missed something. How about the fore-aft trim? I did dive a pair of M71DVB's (3300PSI marked BSM71) which are positively buoyant halfway through the dive. Thanks