Used 3 choc vic sponges cut in half radially, then sandwiched together with nice thick choc butter cream. So you you end u with a stack of 6 1/2 moon shapes. (Chilling for a bit at this stage will help it all stick together - I did this the night before and left it wrapped up in fridge).
Trim a bit off the 'round' side, then stand the whole shebang on the trimmed bit. That makes the fundamental boat shape. Then I trimmed it abit at the back and used the trimmings to build it up at the front, then cut out the bit where the pirate stands. Spread it all liberally with the buttercream. At this stage it looks absolutely crap, do not panic. I used a combo of ordinary choc fingers, Lidl mini choc fingers, but ended up just trimming bigger ones in the end so you could just use the long ones. It's then a bit like building a wall. Put the buttercream into a piping bag (it makes it easier to apply) and piped a bit onto each finger, then stuck to the cake, remembering to leave room for your cannons (those cigar shaped ice cream wafers with candles stuck in 'em). Used loads of silver balls to look like 'studding' and filled any bits in that looked untidy with piped melted chocolate.
Had loads of fun making the treasure chests, stuck 2 brown liq allsort squares together, squashed down well and then carefully carved off the top layer to make a lid, stuck loads of silver balls in with icing, then stuck lid back down. Crows nest was carefully sliced off bottom of an ice cream cone, and used another cigar wafer for the long bit at the front. Bought playmobile pirate for it, and it came with the torch. Masts out of bbq skewers and paper sails. Oh, and choc raisins for the cannonballs. My mil lent me some of her cake making stuff, and I used a little pot of something called 'gold lustre' brushed liberally all over and I think that helped make it look good.
It was loads more fiddly and time consuming than the princess one (that took about 1 1/2 start to finish) but I did enjoy doing it. MInd you, if i never smell chocolate buttercream again it will be too soon. I thought i'd developed ocd coz I was sure i could smell it on my hands for days afterward and had to keep washing and washingmy hands!!!!