bamafan
Contributor
There are lots of people who like the hp 100's especially the true hp 100's that fill to.3500 psi. In sidemount the butts of the Faber lp 85's start to float up around 2000 psi. For most cave diving in Florida this isn't an issue because the dives are normally turned at 2400 psi and with the flow in most caves they are usually not breathed down below 2000 psi very often.
Now there are people who love their old hp100's made by PST and I am one of them. The butts don't ride up and they are slightly more negative than the E7 100's that are so often categorized as hp tanks. The E7 tanks fill to 3442 and are often wrongly called hp tanks.
One of my pet peaves that you see often in Florida cave diving is the use of Faber Lp tanks with no added weight on the diver. This is often the standard practice and works as long as the tank isn't breathed way down. As stated above most cave divers don't breathe their tanks down on a normal dive. Most of them have never done a buoyancy check with less than 500 psi in their tanks. With Faber lp tanks breathed down to almost nothing most divers will not be able to maintain their buoyancy. For some reason most instructors ignore this in their sidemount or cave classes and during an emergency the diver often has to be held down by another diver. I think this is often done because some sidemount instructors use the selling point of this harness trims out without any added weight. It also makes the wing less bulky as less air is needed since adding the weight to be neutral at 10' with nearly empty tanks would require more air in the wing on a normal dive.
So to answer your question there are lots of Florida cave divers diving Faber lp 85's because they do hold slightly more air than hp100's. I don't think you can say that they are preferred though as many more experienced divers prefer the hp100's for their buoyancy characteristics. Either will work just make sure you can hold a stop with nearly empty tanks unlike what many Florida cave divers do.
