I realize the deadline for the challenge has passed. I only learned of this forum and the challenge from This Thread at rpg.net. At any rate, my "entry" isn't a proper map, just a bit of undersea inspiration I created using Poser and Bryce for my undersea D&D campaign.

Within a sunken citadel upon the Sinking Isle, an enclave of mermaid witches known simply as The Grasp now waits. Each was once a slave to a kraken and was mortally wounded, before being saved by a sea hag fleshwarper. The hag, who grafted each of the krakenís tentacles onto the unwilling mermaids after the beast was slain, had stolen the secrets of fleshwarping from the kraken Mikros himself. Now the mermaids have begun to exhibit the krakenís powers and share its memories.