some would buy stuff in certain ports for resale, others took correspondence courses, etc.
We had a couple hustlers on my two ships. One would wait until we got out of US territorial waters, and then basically buy as many cartons of cigarettes as he could. Once out of US waters, cigarettes could be sold without excise taxes. Oddly, that was as true on a carrier as it would be on a cruise ship.
So he'd buy them and then ship them home. A relative had a liquor store, and the relative would just stock his racks. Charge the tax, but never remit it. This was in the 1990s, after Treasury stopped requiring tax stamps on cigarette packages.
Another guy was trying to arbitrage West German marks to dollars...what with the flurry of reunification. He later ran for Senate from his home state, and was thrashed in the primaries...he was intelligent and photogenic, but had a personality as corrosive as my own. AND...he had been a real-life Corporal Klinger in the Navy. He was nuclear waste - washed out of Nuke School - and under a six-year enlistment, and couldn't WAIT to get out and get on with life.
So...already he had a rep for being crazy. He was a Machinist's Mate - the black gang. Well, we're in port, and the Captain is arranging his annual formal inspection of all spaces...this was a Big Deal, capitals, although any savvy CO would know what's going on with his ship. But it was ritual - someone from the division that owns the space is to present it to the captain and answer questions.
He was tasked with this. Well, he pretended not to hear the CO and his DivO come down the ladder, and he took his man-tool, which was abnormal length...and wrapped it around a handrail, pantomined beating it with a fist, and screaming.
The DivO showed outrage, but the CO just looked, said, "Carry on," and turned away. The guy never was punished - after all, he saved the engine spaces from a detailed inspection, saving a lot of grief for the division.
But that was the sort of circus the peacetime Navy had become.
(Sorry for the thread drift...memories...)