In the U.S. Navy School for Underwater Swimmers, we were taught to keep our masks on and our mouthpiece in our mouth until completing an exit. If we had our mask on our forehead, the instructor would yell, "Who do you think you are, Mike Nelson? Drop for twenty!" pushups, that is. Those pushups were with our tanks (those twin 90s) on our backs too. Needless to say, we learned not to drop our mouthpiece or put our masks on our foreheads so that they could be knocked off by a wave. But sometimes it takes a dramatic event to make the point too.
Concerning getting positively buoyant on the surface, there are two things to say about this. First, I was first taught by the my LA County scuba instructor, Roy France in 1963 that at the beginning of a dive, we should be pretty much neutrally buoyant at the surface. He defined this as floating at eye level on a full breath without any buoyancy aid. That way, we could exhale and descend easily. Also, at the end of the dive, with this weighting we would be slightly positively buoyant on the surface. This was before we had buoyancy compensators.
The second thing about buoyancy and being positively buoyant on the surface is that this may not be enough. Many current buoyancy compensators do not support a diver from the front or under the arms, and therefore when inflated will tend to push the diver onto his or her face. The buoyancy compensator is not meant many times to be a surface floatation device, but to compensate for the loss of buoyancy of the wet suit as a diver descends. Therefore, the current back-mounted BCs area trying to achieve neutral buoyancy at depth in a prone, face-down position. On the surface, you need to lean back to get these devices to support you head-up. This is a different learned skill, and should be practiced with the BC that you are using. I designed a BC, which I call the
Para-Sea BC, which would support under the arms and face-up on the surface, but it was never picked up commercially. The current designs leave something to be desired, in my opinion. We used to have a surface float, usually a tube with a diver's flag, for just such a use, but that is not being done currently.
Now, about snorkels and their use in chop. There are snorkels, and there are snorkels; some are better than others. My favorites are the Scubapro Shotgun (no longer made) and the U.S. Divers Company Impulse snorkel (see the photo below of my boys in Hawaii using the Impulse snorkel in about 1986). It uses the principal of capillary action to have the water entering the snorkel travel down the bell, then out a non-return valve in the bell. The inhalation tube extends into the bell and remains pretty dry except in overwhelming wave action. I have not used the current version, the
Impulse 3, but if it is the same principal as the first version, it should do well in chop. I have the newer Scubapro Shotgun snorkel, but I don't think it is quite as good as the original, and its mouthpiece doesn't fit my mouth. I also have the TUSA HyperDry, and do not like it, as it is not completely dry, and it's mechanism for restricting wave action down the tube also restricts breathing. Be that as it may, any snorkel is better than none, and one must learn how to use these in chop or wave situations. The old, J-tube snorkels actually functioned quite well by simply blast-clearing them. I used the Scubapro Shotgun snorkel, which I cut off at the top of my head, on an 18-mile open water fin swim in the 1980s, and it functioned quite well even in chop and with the top part cut down (to lessen dead space for the marathon swim).
HyperDry Snorkel
Impulse Snorkel
Older-style Dacor Snorkel--this had a smooth tube inside, and functioned very well, but needed to be blown clean if a wave came over it.
Theory behind the Scubapro Shotgun snorkel, from their 1980s catalog.
When I dive, even in the river where there is no chop, I continue to keep the mouthpiece or snorkel in my mouth until I have effectively exited. Not only do they provide air if I slip and go back into the water without my fins (I sometimes do a bit of rock climbing to exit), but if I should fall on my face they will provide some cushion to my teeth.
SeaRat
