I dive with both a long hose and a snorkel. But I agree with the others it all depends on where you dive and personal preferences. The mask tug caused by the snorkel in a strong current is a pain and does ruin your streamlining somewhat (it also tends to wobble and bang against the side of your head in very strong current). It also can be an entanglement hazard. I also agree that it is much easier to surface swim on my back.
Why you may ask do I still wear rather than carry my snorkel.
Firstly, the snorkel is extremely useful should you need to be on the surface in rough weather and for one reason or another you can't use your reg (low air, don't want to waste air waiting, etc). I was involved in a rescue situation once and the diver I was pulling in didn't have his snorkel. We were in 2+ meter waves and he had severe difficulties breathing in between being smashed by the waves (he had to be rescue as he ran out of air). A snorkel would have helped significantly.
As for carrying a snorkel in the BC pocket, I really dont see the logic in that. Masks and snorkels sink!! Why would anybody take their mask off and try to put a snorkel on it either while theyre bobbling up and down on the surface or underwater?
Secondly, if you ever had to do a long service swim it is more convenient to use a snorkel and swim facing down. The problem with swimming on the back is that I cant see where I am going.
And yes, those collapsible snorkels do work well.
And ChrisSparks is right, a PLB should be an essential piece of scuba gear (I'm sure many of you have heard of stories of divers left behind). Sea Marshall (
http://www.seamarshall.com/ ) make some very good PLB / EPIRBs. They're the standard issue for the US military divers and oil rig workers. One thing to keep in mind though is that the current frequency used by most EPRIBs of 121.5 MHz will be phased out worldwide by 2009. The much more expensive 406 MHz will become the EPIRB standard.