We had a sailor party for my son's 3rd birthday. I found sailor hats (like the crackerjack wears) off the internet - they are called GOB hats - for all the kids.  My son wore a captains hat (of course! haha)  I made an "ocean cake" by making two round cakes and carving out an area in the top for blue Jell-O which I added "shark" fruit snacks to just as it was setting.  There was a beach area on the cake and I had the sides decorated with candies and goldfish to look like the sea (from a magazine)  I decorated the whole party area with sailor things - portholes in my foyer, familyroom and kitchen, a ships wheel, an anchor, a lantern was on the table and I had everyone wear their red, white and blue. I also had nautical plates and napkins and had red, white and blue utensils.  I served a sub sandwich (get it?! LOL), had goldfish for munchies, made blue punch (Kool-Aid aid and sprite) - add vanilla ice cream to foam up and make "waves" and had a boat pinata. I think it was a wonderful party and all my guests had fun too!