A buried key?

[Pirate Rose]

Go into the entrance on the far left. Run past the dreg/floatsam, and kinda stay to your right near the wall.

You'll come to an area where you'll kinda be on a landing, stand near the wall. From this landing you can see a bunch of davy jones crew, and a broken ship across the way to your left. In front of that broken ship, you'll probably see an urchanfist. Just sneak past everyone and go into the middle of the broken ship. The dig spot will be there.

lol Kinda hard to explain without pics