18th Pirate Party

Hey, has anyone ever had a pirate themed party? I know it might sound a bit childish for an 18th but I know all my friends would be up for it cause its all a bit of fun.
Anyway, i`m planning a pirate themed party for my 18th which isn`t till January so i`m a bit in advance but i`m so excited! I`ve already got a place where I could definatley have the party and i`m planning to invite most of my year at school so it will be a big party.
I`m trying to be really creative and original about it soi its something everyone will remember as my party because 18 is a huge deal to me! I`ve already got great ideas for invitations and some ideas for decorations but does anyone know anything that could make it really special and memorable, and something that everyone will be impressed with?
Thanks xxx