I have read a couple of things about Nachi Cocom Beach Club that might work for you and the young'uns!
"This is a very nice beach club that has everything to offer. You can book a dive trip or rent snorkeling gear here. The large restaurant seemed to be a regular lunch stop for several dive and snorkel boat operators. The beach is nice and sandy, perfect for swimming, but has little to offer in the way of snorkeling. The freshwater pool has an attached jacuzzi and a swim-up bar."