YA adventure - cabin boy becomes captain of a sailing ship

[Craig]

Read this YA/children's fantasy/adventure book way back in early to mid- 1970's. I got it from the school library, so it may have been published much earlier.

It sounds sort of like Treasure Island but takes place on a world that is mostly ocean. Ships sail between isolated city-islands. A young boy starts out as a cabin boy (possibly a stowaway) and makes his way up to captain of the ship (or another ship).

At one point early in the story, the current captain chokes on a chicken bone, which allows the protagonist to move up the hierarchy in the crew.

Thanks for any help/suggestions tracking down this memory from my childhood.

[Kris]

Craig, what are the fantasy elements in the story?

[Craig]

Kris wrote: "Craig, what are the fantasy elements in the story?"

Thanks, Kris. Upon further reflection, I can't be sure this book included any fantastical besides taking place on another planet. There *may* have been weird sea creatures or even mer-people, but I don't recall anything about that. I've changed the post title to "YA adventure".