At Invisibles Reef, the buoy at the reef edge is over 450 feet from shore. I decided it was much more prudent to swim to the buoy on the surface to help maintain my orientation (roughly a 10 min swim, which at my SAC would use up 6 of the 66 available cf just getting to the reef edge). In my case, I wanted to get to the reef and not slowly poke along in the shallows like in W. Palm. I managed to enjoy the shallows on my way back in. On other dive sites I dropped down early on garden eels etc. that I spotted while snorkeling out.
I was simply pointing out that I think its a good idea to equip a snorkel when shore diving (for many reasons), among them a means of conserving air on the way to the reef. Many boat divers abandon their snorkels and don't consider using them when going shore diving. I think most divers "get" that there's lots of life to find everywhere, incl. the sand shallows if they want to spend time there.