As part of a Pirate campaign I have in the works, I have been building and stealing islands to populate my world map with.
One of my original ideas was The Isle of Splinters, which I have created a one page adventure for below:
A small collection of rock "Splinters" jutting from the sea, there reside a flock of Harpies who harass any ship foolish enough to get close.
In my campaign, Esmerelda the Witch Queen, will hold vital information that the players will need to extract from her, in order to find secret Treasure.
I have entered it into the One Page Dungeon Contest, an awesome initiative which produces some fantastic RPG content. If your reading this post, this years entry is likely closed (I entered fairly late!), but there are a wealth of adventures out there, free to download and use.
Perhaps one will inspire you to enter next year?...