I felt pity to throw a broken skateboard away, and this idea might come to the guys who like skateboarding or longboarding.
Hope you'll find it useful! :)

1. Here's the board. All skateboards are covered with sandpaper — so carefully remove it.

2. Draw the outline of your sketch.

3. Cut it out with a jigsaw.

4. Next, carefully sand the edges, smooth them.

5. That's what you get.

6. Make a pattern with acrylic paint. Dry.

7. Cover the board with wax. Take an ordibary candle, melt it and apply several layers.

And this is the final result:

On the other side :)

And now the fish in its midst :) Thank you for your attention!