I have heard informally that a US flagged boat can stay in EU waters
for up to 18 months without paying the VAT tax on an imported vessel.
Can anyone on the list with any personal experience or knowledge in
this area of EU taxation, explain the details of legally avoiding
paying the tax?
have a look at http://www.registerayacht.com/vat/default.asp.
There they claim that you can prolong the 18 month up to 24 month if
you do not use the boat for a while. Or you can leave the EU (go to
Norway, Turkey or Tunisia for instance) for a short time and start with
a new period of 18 month on reentry.