Here's why:

* Shallow body of seawater: Lagoons are typically shallow, with water depths rarely exceeding a few meters.

* Located along a coast: Lagoons are found close to the coastline.

* Surrounded by narrow strip of land: This strip of land can be a barrier island, a sandbar, or a coastal dune system, separating the lagoon from the open ocean.

Let me know if you have any other questions!