Transportation Vacation

Ships leave once a month to carry men sentenced to transportation.
Exile to Australia.
The trip from England to Australia is a long one, and perilous.
Some crew stab their passengers mid-journey.
Others throw them overboard into the ocean.
A few show mercy, and release them in Africa or some island.
The crew then estimates how long it would take to get to Australia, resupply, and then head back home.
And they go on a vacation.
Whores in Madrid? Wine in Paris?
Whatever, as long as it doesn’t involve smelly, evil prisoners.
Until they need to go back for more.