The only "extra" bit of documentation would be a letter from you, the owner, authorizing the captain to move the boat. Beyond that the regular stuff: document, passports, crew list, stores list. PM if you need a template for a letter of authorization.
SSCA Annapolis Cruising Station Beware cut and paste sailors
This is probably obvious, but to add to Auspicious' suggestion, the signature(s) on the authorization letter should match the owner(s) listed on the boat's documentation. It would be a good idea to have the signature(s) on the authorization letter notarized, as well.