Question About VAT for Non-EU Registered Yacht

[PatrickS]

I've contacted the tax and customs folks in the UK, Finland, and the main EU offices with this question, but after two weeks all I've gotten is referrals to the official documentation, from which I can't find a clear answer, and I'm hoping someone here might be able to speak from direct experience...

If I buy a boat in Europe, for which the VAT has already been paid, and register it under a US flag, and then keep it in Europe for longer than 18 months, will I be liable to pay VAT again, or not.

Does the 18 month exemption period only relate to VAT, and is it irrelevant if the VAT has been paid in the past for that yacht, irregardless of the country of registry?

Is there any way a boat for which VAT has been paid in the past, would be liable for VAT to be paid again? What about other kinds of duties/taxes?

Would registering it under a US flag be considered "exporting" the boat from Europe, and after 18 months, could I be liable for some form of import duties or other taxes separate from VAT?

Thanks.