Alternatively, the repair crew don't stay on the ship. Have a mobile team on a faster boat going ship to ship rescuing and repairing ones that can't make it to port again.

Maintenance is not repairs. The work needed to prevent repairs has to happen ever day. A crew at sea doesnt sit around waiting for an alarm. They are tending to equipment, verifying sensors ... even touching up paint is an essential daily task.

Interesting perspective. I hadn't considered that.

Part of me starts to wonder now about building boats that are more resilient, but then I remember that salt water is terrible and surely by now someone would have if it were possible, since we spend so much money on humans doing that maintenance!

If man can build it, the sea will destroy it.

Spoken like a true sailor :)

If you've ever been on a cruise, you'll notice the "crew" (not the staff) constantly painting and maintaining -- even on a brand new ship. If you ask, they'll tell you that they have to constantly work on the upkeep because of the size of the ship (kind of like painting the golden gate bridge, once you're done it's time to start over again).