HIN re-numbered yacht. Is it legal?

Wow, that's a lot of assumptions. He's not your client nor employer. You don't know what the owner is or isn't aware of and you don't know the methods of the captain nor his relationship with the owner. It may be time to MYOB. Besides, you're the one who bought a 65' yacht without even knowing there was no master SR. Something tells me that you guys could match 'oopses' over many drinks.

u mean ... brutally direct .........

I was being (NY) subtle.

hahaha ... well said capn ...

But it's his 7 figures. If he can afford that I'd assume he has hired the advice he needs (surveyor, captain, lawyer, etc.). It's sort of like pointing out a ladies pimple. It's a nice thing to do so that she can put some makeup on it. Of course, if she already knows about it you've done nothing but embarrass her. Whether to point it out depends on how well you know the person and the situation and what the person already knows about the situation.

Just curious

So, how did this situation evolve over the past two years?

i dont think the USCG has anything to do with HIN numbers unless the HIN is reported on the Document.

Im pretty sure the HIN's are issued by the builder.
I think the builder can change the HIN during production before the document or before the sale.

The USCG issue Document numbers.

USCG document number and year of boat goes by the date the boat is first started and not the finish date. it would be possible to buy a new boat in 2012 that has a USCG Document # and year from 2009.

The boat in the OP may be legit but i would be asking some questions and digging a bit deeper.

New Yorkers still smack you in the face and it has little relations to if they are trying to get your money.

Not strictly relevant but approx 4 years ago I was about to buy a used Maserati Quattroporte. A few hours before I was about to pay and take delivery I was contacted by a Masertai main dealership saying the model year of the car I was about to buy had magor issues which were the subject of a redesign in subsequent models and ( what a surprise) they had a brand new unregistered but othetwise identical car that they could sell me for only £5000 more than the used car I was about to buy. I went ahead and bought the newer model but was contacted a few days later to be told the car I had bought had a manufacturer's recall. when I asked how it was possible for a brand new car to be recalled in this way I was informed the car was not in fact the current model but was an unregistered car that was in fact 4 years old - most surprisingly, it was in fact an older morel than the used model that I had been warned off buying. After threatening litigation I was offered a £10,000 rebate (which broufght the cost down below the cost of the used model) and the opportunity to buy a replacement car at cost within 3 years.

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Buying Italian machines when there are German machines everywhere...