Owners of large vessels will normally go with the "Federal Documentation" method as applied for with the USCG. There is an initial federal "documentation fee" and that's it. You request an annual "stamp" to keep your documentation current, keep the vessel name and hailing port clearly marked on the transom (among other requirements) and float on. There are no state numbers, no state registration, no state fees and on top of that, a state entity cannot board your vessel without yours or USCG permission. I'm not sure if there are any limits on vessel length to obtain federal documentation status.
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