Mmmmmmmmmmm! What kind of boats are we talking about? Most of the ones I know of are out of production but I see on ebay a lot such as the following examples:
Lindberg Sport Fisherman : I can't remember the scale, but its about 32" long of a Donzi sport classic that was suitable for RC.
Lindberg's "Fishing Boat" classic series. This had a North Sea Trawler, Shrimp Boat, and Tuna Boat. These can also be found under "Life Like".
Monogram "Miami Vice" Scarab.
Revell makes a Bass Boat, which is probalby not common off the coast of Africa or Maylasian Straits.
From what I have read, these pirates operate like opossums. They either attack at anchore / port, or play distressed in a old "fishing or refugee" vessel and then divide and overtake the unsuspecting crew. They then steal the ship and take it to a "chop" yard to unload and sell the cargo and either dismantle the ship and sell the parts / scrap, or they reconfigure the ship for either their use, or to resell it.
They have been known to do this with an entire 800' container ship.
Pretty interesting subject you are going to do.
I know of many more kits that might work, but my brain just won't engage at this moment.
Scott