Buying a car in US and registerig it there.

I am Canadian and I own a house in Florida. As a Canadian can I buy a car or boat and register it to drive it in the US and Canada? Can I get a US drivers licience, or can I continue to use my Canadian licience?

I think the state of Florida only will let you get a state driver's license if you have some sort of immigrant status that allows you to stay. Visitor status does not.

Google "DMV Florida"

I believe FL is one state that allows Cdns specifically the ability to get a DL without an SSN and without an immig status. They may need a letter from SSA saying that they have never been issued an SSN.

Florida is an exception to this general rule, you can as a Canadian citizen get a DL valid for a year merely with proof of Canadian citizenship. You have to surrender your Canadian DL, you can't hold both at the same time.

Whether it's a good idea to do it though is another question. Usually it comes up for example when someone spends a lot of time there and keeps a car there but doesn't have one in Canada. Obviously if you have a Florida DL that may cause you problems in Canada with your car insurance or whatever.

As to registering things, the best idea is usually to register it wherever your principal residence is if you plan on crossing the border with it, otherwise for example if you have a Florida registered vehicle but live primarily in Canada and cross the border with it, CBP and CBSA will consider you to be importing it and you have to pay duty, comply with all the paperwork requirements, etc.

Note that the need to to surrender your Prov DL is by vurtue of specific agreements in place between FL and some Provinces.

There is no general law or universal agreement beteeen states and provinces that forbid holding "one of each".

I know, for example, that Missouri does not exchange or invalidate Prov DLs when a MO DL is issued -- unlike all other state DLs. When asked why not, the response was that they don't have any agreement between us and the provinces.

The "advantage" that a FL sojourner would have getting an FL DL is for a car bought, plated, insured and usually left there when back in canada.