I'll add one more to this thread:
Looks like Legal Seafood opened docks at its Boston Harborside location this season:
Legal Sea Foods - The Standard for Quality and Freshness in the Restaurant Business.
Note says "And transient docking for boats is available in season at the Liberty Wharf Marina."
Information | Docks | Marina | Liberty Wharf
$20/hr, 1hr minimum. That could be an expensive lunch...