What's the difference between boatage and wharfage?

Boatage

Definition:

• (n.) Conveyance by boat; also, a charge for such conveyance.

Example Sentences:

Wharfage

Definition:

• (n.) The fee or duty paid for the privilege of using a wharf for loading or unloading goods; pierage, collectively; quayage.
• (n.) A wharf or wharfs, collectively; wharfing.

Example Sentences: