If you have been on ships at sea, you know how interesting it is to watch pilots embark or disembark sometimes miles from land, in all weather. The pilot takes over a ship, more or less, when approaching land.
It is not easy to become a US Pilot.
Pilot boats are the toughest small vessels, with master handlers. Sometimes pilots have doors to enter a ship. but often ladders as in this photo. In bad seas, they jump.