Man, you almost managed to get another terrifying snorkelling nightmare in my head as the idea of a wasp or bee buzzing in my snorkel (and then my mouth) is beyond disturbing but then, I realized I have never seen this kind of insect around the coast, let alone above the water surface so I think we do not need to worry about that too much ;) But unfortunately, snorkellers getting hit by jet-skis do occur and with the traffic around the coasts constantly increasing, we should be really careful...