There's a reason cetaceans have a breathing hole on the back of their heads. On anchorline deep dives I may carry a fold up snorkel in my leg pocket. Otherwise, it's always there, unobtrusive, tucked neatly on the side of my head, instantly deployable. I've heard people say that snorkels break a streamlined profile. Sometines these people have incredible amounts of junk hanging off them, with clumsy BCs that look like winter overcoats and more hoses wrapped around them than the Michelin man.
I once swam more than a mile to a small boat that had drifted because the kid in it had fallen asleep. There were two of us, the Jamaican small shop operator and me. On the surface, looking at the faraway boat, we fully inflated our BCs, took them off, made small semi-buoyant rafts out of them, and slowly snorkeled, pushing our equipment, toward the boat, which happily was drifting shoreward. It was actually lots of fun, relaxing, got to see a lot of things as the bottom slowly rose and turned to turtle grass. I learned many new Jamaican words that afternoon.