In that case, the best use might be the "isolate mild cases" approach: everyone who tests positive goes on the ship, even (especially) if they don't have symptoms. If they deteriorate to severe, move them to a real hospital. This has been a big part of the Wuhan campaign.
I doubt that. It’s more likely to depend on the viral load you’re exposed to. Being a nurse with inadequate PPE intubating someone and being exposed to large quantities of COVID once will give the virus a head start, whereas running through a cough cloud and just barely getting enough to infect you five times over the course of an hour will give your immune system a head start.
