Spits
A narrow bank of sand that projects into the water form a bend in the coastline is called a spit. A spit, which forms where a shoreline changes direction, is protected from wave action. When a growing spit crosses a bay, a baymouth forms.
Baymouth Bar
A baymouth bar forms when a spit closes off a bay. The shallow, protected bodies of water behind baymouth bars and barrier islands are lagoons.
This is a picture of a growing spit that crosses a bay in which it forms a baymouth. When searching for this picture on Google Earth, it was hard to find it, but it still exists today.