The very first time I went on the ocean in a sailboat we were heading down a river towards a drawbridge when the captain (my dad) suddenly "had to use the head" and handed the wheel
to me and pointed to the VHF radio
so I could request a bridge opening. He knows a fair amount about the right way to do things, but tends to panic under pressure and also has a certain disregard for following procedures.
I managed to stumble my way through the procedure even though I had no idea of the mast
height, the opening schedule for the bridge, the name of the bridge, what channel it monitored, or what the relative tide/current situation was. We were lucky nothing was broken and no one was hurt.
At that point I decided to learn everything I could about seamanship and had several long conversations with my dad. Even on his boat, I insist that he designate one of us, in advance, as the captain for any given procedure as this gives both of us time to plan out our respective duties.
Not exactly a "couples" situation, but whenever family
is involved it's best to delegate all authority in advance so no one gets sad. I prefer a permanent captain, but as long as agreement is reached prior to a situation developing, then things can still go smoothly enough.