Not sure if kelp is supposed to grow one sunken ships or not but I found one that was covered in it. Except the kelp wan't actually touching any of the wood blocks. It's just floating one block above them. However, the kelp is sitting directly on the fence railings.

Also the railing it's on isn't connecting to the railing next to it? Not sure if those two things are related.

Edit: Kelp is also growing on the treasure chest.
Edit 2: I found a fence with no kelp that is also unconnected. So I guess they are not related. Should I create a separate report for the fence?
Edit 3: Found another ship where kelp is growing on the wood blocks. The railing here is also broken.

seed: -8300275442758179407
xyz: 514 56 1536 (floating kelp)
xyz: -407 50 2254 (attached kelp)