Pretty good entry!
It's funny that 2 shipwrecked-type entries were posted on the same morning.

I love the exp
ressions on the faces, they really add a lot to the feel of panic. Another thing that you've done well is adding some debris in the water, which makes it much more interesting.
It's a shame that you have to use a webcam, because the pictures from that will never do this justice, but ah well.
Some improvement ideas:
1) I would recommend reversing the direction the the raft is facing, so you don't have the unsightly bottoms of the bricks showing. Then you can tile the top for a perfectly smooth look.
2) Like the others said, definitely try to make the raft a bit more jagged, so it looks like it's really been blasted off.
3) Your entry feels a bit too flat in the color area. Primarily because it uses solid blocks of one color, like the plain blue water and the all-brown raft.
This could be improved dramatically by inserting some splashes of a different color in some parts. Here are a few ideas:
You could mix some light blue, white, and trans-clear plates (or just 1 or 2 of them) in with the water, which will make it much more exciting to the eye.
Placing some spilled jewels and coins around the treasure chest might be nice.
A black lantern on the wall.
Putting some black or dark brown plates in between the layers of brown on the bottom of the deck.
The ever-popular parrot perched somewhere.
Any of these things would be welcome additions, and will make your entry so much more interesting.
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Overall, you have an excellent start on this, and I look forward to seeing your progress in the near future. Good luck!