I used my favourite chocolate cake recipe for this. I baked 3 whole batches, 1 batch per tin and it baked at the same temp for around 35 minutes in the 10" square tin
https://cookpad.com/us/recipes/333461-vickys-best-ever-chocolate-cake-w-secret-avocado-gf-df-ef-sf-nf
One of your squares is for the cake base. Slap the blue frosting over the top and sides. Don't be too neat with it, it looks like choppy waves if you're a bit rough with it. Put it aside
The other 2 squares need sliced in half
Carve the top of each of the 4 rectangles you have to shape the bow of the boat
Level off 2 of the shapes if necessary then using a thin layer of chocolate buttercream, sandwich one layer on top of another
Repeat for one of the other layers. Spread the top of what you've just constructed with a thin layer of frosting and put the next whole layer on top. You now have 3 whole layers stacked on top of each other
The last boat shape you have left needs to be divided into pieces. (I got overexcited and cut 2 of my layers but you only need 1 cut up. The first cut is where the front triangle meets the rectangle, so the bow shape at the front. Then the rest of the rectangle you're left with needs cut into 3 pieces. So imagine my picture, where the square is in the middle, also cut in half and the thinner end piece makes the 3rd bit
Now I must apologise for the lack of pictures for the assembly of these pieces. What you need to do is put a thin layer of chocolate buttercream over the top of the 3rd whole layer of the boat shape you've got going
Now stick the front triangle on top of the other triangle shapes and stick one half of the middle square you halved onto the back for the stern. Coat the stern piece you've just stuck on with frosting on top then stick on top the thin end piece which should be half as wide as the piece under it. The remaining piece is your treat! We don't need it so enjoy! Now coat the whole of the ship with the remaining chocolate frosting
I used wooden kebab skewers cut to size to hold the cut pieces on, so I put 2 through the back step on each side and 3 through the front triangle to keep it in place
As you can see, I was quite slapdash with frosting the ship. My plan was to smooth it down and use a toothpick to mark out wooden planks to make the ship look nice but I didn't have any room in the freezer to chill the cake before I started decorating and the more I spread the frosting the more cake came away with it. Nevermind, you'll make a better job I'm sure
Now employ an extra pair of hands and place the ship on top of the sea! The frosting is easily fixed after it's been lifted and stick on anything that needs to go on the cake side before the frosting dries
Next I melted around 50g of dark chocolate in the microwave and when it was room temp I tossed some mini marshmallows in it. I stuck them on the sides of the deck and used 2 strips of the bar that was leftover to finish off the railings
Now you can add any decoration you like. I got edible wafer sails, cannons, ships wheel, anchor and map from ebay for a couple of bucks. I got the fondant pirates from the local craft bakers and the candles from the supermarket. The shark was an old toy of the boys!
