Ship's Quartermaster

Quartermaster. The quartermaster plots the ship's course, relying on knowledge of nautical charts and a study of weather and sea conditions. A reliable quartermaster tends to have a high Wisdom score, as well as proficiency with navigator's tools and the Nature skill.

Four other officers: a first mate, a bosun, a quartermaster, and a cook (nobles)

After Captain, the most authority on a pirate ship had Quartermaster. As a Captain's right hand, he was in charge when Captain was not around. He had the authority, and he could punish men for not obeying commands. Quartermaster was also in charge of food and water supplies.