Boating

TL; Must Specialise; DX/Average;
Defaults: DX-5 or IQ-5.

This is the ability to handle a specific type of small watercraft. For large vessels that require multiple crewmen on a “bridge,” use Seamanship (see Crewman, p. 185) and Shiphandling (p. 220).

Make a roll to get underway, to dock, and whenever you encounter a hazard. If using this skill at default, also roll when you first enter the boat – to avoid falling in the water!

You must specialize:

Modifiers: -2 for an unfamiliar boat within your specialty (e.g., a kayak when you’re used to a rowboat); -3 or worse for foul weather, navigational hazards, etc.

Source: GURPS 4th - Basic Set - Combined, page 182