Hi , I dive some of the same waters as you, hang out in Lund, have had a variety of guns and the best of all is a rife, I use it mostly in Mexico and it's way too big for up here, but they make smaller models as well, you probably want something around three feet long, maneuverable, so you can shoot in holes. I've had a few smaller guns that are very popular and used them here but the rife product is way better. Cheers.