A Pirate's Things
Request that participants dress up in pirate garb for the treasure hunt. The costumes can cause quite a commotion if the treasure hunt takes place in public, and pictures will create memories worth a thousand words. Outfit each pirate with a treasure map, compass and spyglass.
Maps
Maps, specifically treasure maps, are a prized possession among pirates. Give each team a piece of a treasure map with a riddle or clue to find another piece. By the end of the treasure hunt, they should assemble their map to find their treasure. This could be the final meeting place, especially if it's a surprise.
Build anticipation from the start by delivering a small piece of a map in a glass bottle with sand and gold foil-wrapped candy as the invitation. Have each team meet at a different location. Their next clue can come from the location, or from each of their maps put together.
The Hunt
Send the pirate groups on a treasure hunt through town, if transportation is available. Have a list of tasks or treasure that the pirates need to complete (with picture or video proof) and gather, with each task having a certain point value. Make it a rule that items cannot be purchased, stolen (except from the other team) or brought from home. Add a rule about everyone staying in character, even talking like pirates, to make it more fun, but forbid the pirates from telling others that they are involved in a treasure hunt.
Have the teams try to get strangers to wear pirate gear, sing pirate songs, act out famous scenes from pirate movies, name famous pirates, get a gold coin from a stranger, find a live parrot or any other pirate-related tasks you can think of.
Treasure
Fill a treasure chest with treasure for the winning team, such as candy wrapped in gold and silver foil. Give the losing team a chest full of gag gifts, fake bead necklaces or other secondary gifts. Watch the videos, or put a slide show of the pictures together to view as a group. The winning team can share their booty with the others if they choose.