Do-It-Yourself Letter of Marque

The attached document is a real letter of marque from the National Archives of Canada (RG 8 IV v.139) with blank spaces provided for the name of captain, ship, and crew. Blank letters of marque like this were printed up by colonial governors. The blanks were filled in by hand when successful applicants posted their security bond of 1500 pounds and met the other conditions listed in the letter of marque.
TIPS
All you have to do is print the attached letter of marque and fill in your own name as captain, along with your choice of vessel name and appropriate weaponry (I suggest a 100 ton schooner with 10 nine pounder guns and a crew of 70, but you can make up your own mind. Some privateers carried only a handful of men with muskets.)

Now just find a Lieutenant Governor to sign and seal it and PRESTO! you can set sail with your own private warship.

Create your own Letter of Marque.