I've not met you Jerry, but I understand that "in person", you're not very weird. ;^)))) A number of relatively "normal" people have told me that.

If you have a foreign flagged boat, leave it anchored in the temporary harbor location unattended; it's not too unusual to call the boat abandoned.

If the boat was a US flagged vessel (or even registered in one of the US States), then they could locate the vessel.

If someone left a boat in a harbor in (say) France and disappeared, what do you think would happen when the local Harbor authorities couldn't locate the owner for months after the boat was left unattended?

Who does the guy think he is? Sounds pretty irresponsible to me. A reasonable person would have contacted the Harbor Master (or some Federal Authority, Homeland Securitity's Coast Guard or Customs, etc. instead of dropping the hook and disappearing to whereever.

The word abandoned may have meaning in this case, in my opinion. At least reckless abandonment.