This is a unique idea that is also so easy! A pumpkin snorkeler. The only carving you need to do is the mouth. The eyes are painted on. And yes, the snorkel fits in his mouth. Don't forget to sit him on top of a pair of flippers to complete the effect.
For this fish food chain Jack-O-Lantern, use the mouth cutout and attach it as the fish's tail. Use your imagination. You can do just one great big fish or make a food chain like this one with varying sizes of pumpkins.
This picture didn't come out so well, but that is a shark design carving done on a fake craft pumpkin. When it comes to carving pumpkins, you don't have to do the boring triangle eyes/nose with crooked-teeth mouth any more. The possibilities are endless. Carve a palm tree silhouette, a sailboat or a beach umbrella. Use your imagination and you can have a "beachy" Halloween this year!