Hi PilotFish,
I was using the snorkel during my novice days until I realised that most, if not all, experienced divers, did not use them. Without the snorkel dangling from your mask I find it more comfortable and being more streamlined it conserves some air.
However, there was an incident in my 66th dive when I had to swim against strong current from the stern of the boat to the bow to descend down the anchor line. The waves were choppy and water keep rushing into my mouth. I tried using a regulator and it just free-flowed. How I wished I had brought along my snorkel!
Since then I've tied two short loops of bungee cord to the bottom holes of my back-plate to hold my snorkel in a horizontal position snugly behind my back. It doen't get in the way, no risk of entanglement, my streamlined profile is intact and if I surface in bad weather it's there for me.