Hello toot toot
And welcome to Rootschat!
The pay website findmypast.com has overseas indexes for births, marriages and deaths. I think you can check for a name for free, but you would have to pay to see the record.
It would be pure speculation about why his mother was at sea at the time. Do you have her birth details? Is she British? What about his father? If one of the parents was British and one American, she could have been travelling from one country to the other, to join her husband or to be home for the birth (though it didn't work out that way!)
MarieC