I received my first ever personal request to show up in a thread, so of course I had to (and I am sure you were all waiting for me :D). Here’s my take:
I am a currently serving officer in the Canadian Forces. I asked another officer (Armoured RECCE) for his opinion as well, here’s what we came up with (we had to try and remember how different the navy ranks are, so thanks for that!). These answers are based on our own experience:
Hypothetical 1
Capt. Adams, the commanding officer, leaves the Bridge and tells Lt. Barnes she’s in charge. Adams leaves and doesn’t come back. The ship falls under attack and Adams can’t be found or contacted. Cmdr. Cooper, who was below decks earlier, rushes onto the Bridge and says, “I relieve you; I’m in command now.” May Barnes relinquish command to Cooper? Must she?
Lt Barnes has essentially become the “duty officer”, which is common since no one can be in awake and in the TOC (Tactical Operations Centre) all the time. She would remain on duty until someone relieved her, at which time she would stay there to help run things and make sure whomever assumes command is in the “know”.
Hypothetical 2
Adams, Barnes and Cooper are all on the Bridge at the same time. Adams hates Cooper and doesn’t trust him. May Adams tell Barnes she’s in charge and then leave the Bridge, even though Cooper is right there and is ready, willing and able to take command?
*This one gets a little trickier – what position/appointment are these officers in? The reason I am asking is that there may be a senior-ranked officer that does not have the training necessary to defend effectively against an attack (for example, what if you had a visiting musician from the marching band that was a higher rank?), but can run day-to-day things until the Captain is back. Still – yes the Captain would be expected to hand command to the DCO and if not, that member would have grounds to file a grievance. If there is a severe reason that the CO doesn’t trust the DCO, then they should move to have them suspended and put an Acting DCO in their place. *
Hypothetical 3
Adams leaves the Bridge and tells Barnes she’s in charge. The enemy attacks and Adams and Cooper are both killed belowdecks. The ship is badly damaged. Barnes has lost all hope but is still mentally sound; she decides to relinquish command to Ens. Dobbs, a callow young line officer who just happens to be standing there. May she do so?
*If she can’t/won’t do it, she’d better hand off to someone! Also, if she does it because she is genuinely combat-incapable (or seriously inexperienced), then it’s actually the correct choice; however she would remain ultimately responsible for the outcome. If she has lost her nerve and shirks her responsibility, but has all the same/similar training, then she would be charged. *