Being registered in Delaware is to say you can operate in Delaware and keep the boat in Delaware. If you register in Delaware but then stays an inordinate amount of time in another state you may trigger invalidation of the Delaware registration not from the State of Delaware but from the state you spent too much time in. They will then demand you register with them.
State registration is not universal in that you can't register in Delaware them move the boat and keep it in Maryland
. Suddenly Maryland
will demand you be registered with them and pay all the fees
owed to them. Maryland will say you boat now meets the requirements that it be registered with them and you Delaware registration is considered void to them. Delaware won't care. Maryland will damnd you unregister in Delaware first then register and pay them. Maryland is an expensive state. All states have their own different rules concerning use fees
and sales taxes.
In sorting it out state to state don't confuse your resident status with the boat. You rboat can be perfectly legal longer than you can as a non US citizen. You get some limit exemptions as a foreign visitor on some taxes but there are time limits that vanaish if you state register. The rules concerning all the various time limits are your responsibility alone so check each state you plan to spend more than 60 days in.
Taxes in the US are presumed owed until you prove you don't owe them. It's not like a crime where you are innocent until proved guilty.
In summary if you keep a boat in any state long enough you MUST pay fees or move onn before the time limit expires. If you trigger the time limit and they find out they can and will come after you adding criminal charges on top of the rest. If the boat is foreign flagged then as a visitor you get a period where you are exempt under federal Immigration law of all state fees / taxes. Registering a boat in a state is legal for you as a visitor but your boat subject to all laws and taxes as any resident.
In states that charge sales taxes, use taxes or personal annual property taxes you can owe those even though you are not a US citizen or even a resident in that state. It's about the boats location not you. If a boat stays too long in one place it owes the tax and you must pay it.
For US citizens US documentation
saves state title registration but does not save any state taxes and other fees some states may impose. Only a US citizen can get USCG documentation
on a boat.
Personally, I think Delaware is not a good choice to keep a boat mostly because Delaware isn't that great a place to sail and the winter gets a bit harsh. So from my own point of view the savings in taxes are offset by a poor place to keep or use a boat. It's close to NE cities but not close to any place you might want to sail. At some level you want your boat where you want to use it the most. If you need to fly in and then take off offshore to all your destinations it could work
. The Delaware River is not trvial with strong current
and heavy traffic. Slip fees are not particularly cheap
but they are not cheap
any place that far north.