I think that over time it will become obvious who plays what role onboard. On a boat with a couple rarely is one of the two responsible for every decision. I would call the relationship on our boat, co-skippers. Blue and Gold watches if you like.
There is a tide in the affairs of men,
Which, taken at the flood, leads on to fortune;
Omitted, all the voyage of their life
Is bound in shallows and in miseries.
Shakespeare, Julius Caesar IV, iii, 217