Steven Blanchard:Surface swimming (especially in chop) is only one of the purposes of a snorkel on a dive.
But its entirely unncessary for that. You can provide plenty of bouyancy, you can use your reg, you can swim on your back all perfectly well without a snorkel. Its NOT needed for this.
A snorkel is a tool.
Its about as useful as an electric lawnmower in the sea.
Fixing/adjusting you or your buddy's equipment while in the water can sometimes require having the face in to see what you are doing. Previewing your descent also reqires a face down position. Using your reg is a needless waste and holding your breath is tedious.
Do the air calculations of 30 seconds or so breathing at 1 atm/surface pressure. You'll find it so small to be utterly insignificant and not even noticable.
Entanglement is a matter of knowing where your space is and proper positioning. In my 28 years of diving, I have to admit that there times when I wondered why I wore mine, however when it is needed and used, it always pays off.
It limits what you can and cant stick your head into, simple as that. For all the use it us you may as well ducttape a large plywood plank to your head to achieve the same limiting effect and use underwater.