Sea Base Sister Crews

[69RoadRunner]

We're doing the out island adventure this summer with 2 crews. For that adventure, do the sister crews camp together and sort of operate as 1 large crew?

We have just 4 adults for the 2 crews and I'm not sure we could have a last minute replacement if someone got ill. Would the 3 adults be able to cover for the 2 crews in that case? I think our 4 adults will be fully vaccinated by then, but of course other things could happen as well.