There are two ways of “registering” a vessel in the United States. One is through State Registration with a State Title (in this case, Wisconsin) and the other is through Federal Coast Guard Documentation with a CG-1270 Certificate of Documentation.
You cannot have both a State-issued vessel Title and Coast Guard Certificate of Documentation concurrently. When you purchase a vessel, it may be either State Registered or Federally Registered with the Coast Guard (or both), but only one ownership document is issued. To Document a vessel or process a Deletion from Documentation, the process requires a notarized CG-1340 Bill of Sale and the completion of either a Transfer or Deletion webform, located at these links below:
Transfer of Vessel Ownership (CG-1258)
Deletion from Documentation (CG-4593)
According to the Wisconsin DNR Website: “Federally documented boats operating on Wisconsin waters must also be registered in Wisconsin if Wisconsin is the state of principle use or if the boat has been used in Wisconsin for a period in excess of 60 consecutive days; only exceptions being documented commercial fishing vessels with a home port located outside of Wisconsin operating on Wisconsin waters for 60 consecutive days or less. Applications for registration of federally documented vessels must include as part of the application a photocopy of the front and back of the federal certificate of documentation for the vessel. The federal certificate of documentation must be current at the time of applying for registration. If you purchase a vessel that was previously documented by the US Coast Guard and you intend to title the vessel in Wisconsin, you will need to submit the letter of deletion from the previous owner(s), showing the vessel was deleted from the USCG registry.”
If this vessel has been recently Documented by the previous owner, you will not be able to obtain a CG-1270 Certificate of Documentation unless it was provided by the seller (previous owner). In these cases, you will be required to file a Deletion from Documentation in order to proceed with your Wisconsin State Registration [external link].
https://dnr.wisconsin.gov/permits/registrations/boat/CoastGuard.html