I was remembering an old story I read where the mc is a Merchant Marine, and ex-regular Marine, He's serving on a vessel and either a lotto or something occurs to cause him to first buy a togboat of his own which he refits and builds up to have a business of its own and the crew end up being a few women he has a relationship with, after a time they grow apart and he sells them that vessel and he gets himself another. Develops some sort of missile defense system and starts to transport fissionables around the world with various other romantic entanglements and crew etc.
I've searched a bit and haven't seen anything like it around but I do recall it. It's a LONG tale so should be hard to miss.
This one ring any bells?