Take a look at Chilies, the Dolphin Hotel, or our cabins which range from $20/ night to $45/ night. These are all very close to the water, about 30 seconds walking real slow. If you don't have your own snorkel gear, it can be rented from the marine park for 5 bucks a day. As to where to go, try Half Moon Bay, here in West-End. That's where we do our confined water training. This week my students saw a seahorse, permit, a stingray, banded coral shrimp among other critters. This was all in about six feet of water. If you snorkel to the right and left of the bay, you will see plenty more. You may even find Stanley Submarine's first vessel which he sank there.
I would also suggest heading over to West-Bay where it is absolutely beautiful. If you walk down to the end of the beach you will see all kinds of stuff while snorkeling around the dive site, Black Rock. You can walk to West-Bay or take a water taxi for about 50 Lempiras.
Good luck...