I've a question regarding a "Maritime Mobile" contact I made late this afternoon...at 2347 UTC I worked N1ZZZ/MM on 28.405, who said he was currently, at that time, in North Pacific, in Grid BM14. What country does a contact like that count for...the home location of the ham broadcasting from the ship, or the country closest to where he's broadcasting from? And how would the location be verified, if for instance the ship were going across the ocean over a period of time?
I know it's nothing to get overly excited about, nothing rare, etc., but I just got my Tech. Lic. in August, so most contacts I make outside of AZ is a first for me, and I get excited

... So I was wondering how this contact will count in my list of locations worked when I get it sent to LoTW?
Thank you for your time and assistance;
Raymond - WF7BSR