I had this idea ages ago. Originally inspired by Black Lagoon it was a basic roleplay about a simple crew doing odd jobs. The location would be somewhere in Southeast Asia, either Vietnam or Thailand. Somewhere where there is 'law', but they're incredibly corrupt and we take full advantage of it.
I always imagined it at like a crime drama like something David Finch would direct, we're all fucked up people, exiles or refugees that are just trying to use their terrible talents for the best reward possible. We all deal with the amoral tasks that we're constantly assigned, directed by the Captain who, yes does terrible things like drug smuggling, gun running, raiding of ships. All of us are at least partially aware of the lives we take and all of us have resigned. Some of us turn to god, some of us will turn to our own twisted or modified morale compass. Some of us may even turn to insanity.
One thing is true though, we'll all have to trust each other and develop a sense of camaraderie or we're all dead in the water.