An oarlock is a U-shaped metal or plastic device attached to the side of a rowboat that holds an oar in place while you row. Think of it as a sturdy bracket that keeps the oar from sliding away when you pull it through the water.

Without oarlocks, rowing would be nearly impossible. Imagine trying to push a boat forward by holding an oar in your hands with nothing to brace against: the oar would slip backward through the water instead of pushing the boat forward. The oarlock gives you a fixed pivot point, so when you pull the oar's handle toward you, the blade pushes hard against the water and drives the boat ahead.

The oarlock swivels to let the oar rotate smoothly through each rowing stroke. You can also lift the oar completely out of the oarlock when you reach shore. On older boats, you might see wooden pegs called thole pins instead of metal oarlocks. These served the same purpose but were simpler and quieter. The squeaking sound of oarlocks is so distinctive that it's become a signature sound of rowboats in movies and stories about fishing trips, lake adventures, or escapes across moonlit waters.