A vessel crowds another when it infringes on the stand-on vessel's safe maneuvering room, forcing the privileged ship to alter course to avoid a collision. This violates the collision regulations by removing the safety margin required for large ships that take miles to stop or turn. Pilots and captains use the term to describe aggressive or negligent boat handling in restricted waters.
Heard on the job
Tell that sport fisher to back off, he's starting to crowd us and we've no room outside the channel.
Insider tip
Crowding a deep-draft commercial vessel in a narrow channel is a quick way to get reported to the coast guard.