Ah yes, pirates.
Ooh arr me hearties etc etc.
DS2 had one last year. Flap a fish was a big success actually, tho I did have 3 older children to help on the teams.
Also did pirate island on big sheet of paper, squared it off and "hid" treasure on one square; they all had to pick a square (I told rambling and apparently engrossing tale of pirate coming to my door with it) and winner was revealed at ehd.
Treasure hunt round room for gold coins (cardboard)
Pin eye patch on Johnny Depp (numbers need to be small)
Musical islands
Pirate craft - make pirate masks
Food wise - cake can be treausre chest(v easy and fab) or pirateship (with Playmobil people on). Also did fruit cutlasses (on wooden skewers) which were such a big hit have done them at every party since
Party bags; loads of stuff online. IIRC they got pirate notebook and pencil and stickers, gold coins and a pirate balloon.