If youre travelling just 'state to state', etc. ....:
•Be sure to have a cert'd copy of your original bill of sale AND cert'd copies of ALL recent (state and local) tax bills paid on the boat.
•USCG Boat documentation papers or state registration documents.
•Many states now are beginning to require a contemporaneous written log of pump-outs ... keep those 'receipts' as backup documentation.
•All insurance info/documents - receipts.
•In those states that now require 'safe boaters courses and ID', an acceptable 'equivalent' issued from your home state or other state .... check Boat/US 'state government issues' website.
•Keep receipts from marinas, restaurants, pump-outs ... to prove your 'whereabouts' especially when having to prove that you were in or 'entered' a state with a 'taxation grace period' .... before applicability of ALL sales/excise/etc. (or differential thereof) of taxes due, etc. ... if you exceed that grace period, those records are 'admissible'. Check the Boat/US government affairs website.
•Firearms (where permitted) photocopy of serial number ON firearm, copy of orig. bill of sale. If applicable for 'reciprocity' - copies of CCW permit.
•Photocopies of all drivers licenses, credit cards, CCW permits, etc.
•A comprehensive list of serial numbers of all equipment that can be 'stolen'- electronics, dinghy, outboard, camera, etc.
Traveling to 'offshore' and other countries.
all of the above +++:
•Photo-copy(s) of your passport.
•Back up cert'd/notarized copy of your birth certificates.
•DTOPS 'stickers' and paper copy of same - ABSOLUTE REQUIREMENT for reentry to US as per DHS.
•Copy (should be notarized) of 'planned travel itinerary' that you filed with the USCG/DHS before you left the country.
•Cert'd copies of all animal (pet) importation forms - need these BEFORE you arrive in foreign countries.
•Copies of pet's health certificate.
•Photo copies of any "local boater" immigration cards (and receipts). LOCAL BOATER ID CARD (and cellphone) strongly recommended for reentry into Florida ... so you dont have to endlessly 'traipse' off long distances to official entry points & within 24 of arrival.
•Firearms (where permitted) photocopy of serial number ON firearm, copy of orig. bill of sale. + ammunition inventory.
•A comprehensive list of serial numbers of all equipment that can be 'stolen'- electronics, dinghy, outboard, camera, etc. (with copies of orig. receipts) .... & to help prove that no 'import duty' is needed if challenged upon your return.
•Up to date flares, etc. .... up to date for when you 'arrive' back into US.
•Comprehensive itemized list of all prescription medications onboard (with copies of prescriptions for 'opiates', etc.)
•USCG Boat documentation papers or state registration documents. State registration NOT accepted in "French" islands and territories - HEAVY fines.
You dont NEED most of the above; but, if you get into a tax or reentry 'cluster festival' you will be sure glad you have such with you.
Happy travels. ;-)