A LAKE is a body of water surrounded by land, typically with a smaller surface area than a SEA or ocean. An island is a piece of land surrounded by water, and is usually much larger than an ISLET or ISLE. A LAGOON is a shallow body of water separated from the SEA by a barrier island, coral reef, or sandbar. An ISLE is a small island, while an ISLET is an even smaller island. Finally, a SEA is a large body of salt water that is partially enclosed by land.