Maritime Defense Force

The Maritime Defense Force is a group from The Legend of Zelda: Phantom Hourglass. A group dedictaed to protecting the seas in the World of the Ocean King, Nyave is the only known member of the force, but it is clear through in-game dialogue that he is not the only member.

When Link meets Nyave, he tells Link about the Maritime Defense Force, and how he joined it to be more like his older brother, the Self-proclaimed Hero. Nyave, however, is not the best peacekeeper, and he has lost his Guard Notebook which is presumably a manual needed to successfully be part of the Defense Force. When Link obtains the Guard Notebook and returns it to Nyave, he explains to Link that his boss will no longer need to yell at him.

Theory
The Maritime Defense Force is rarely mentioned, and the identity of the "boss" that Nyave refers to is unknown. Although the leader of the Force may very well be a character who is never seen, it is possible by the way Nyave talks about him, that his brother, the Self-proclaimed Hero, is the leader of the Maritime Defense Force.