How often, if ever, did a medical officer declare a naval captain "Unfit for command"?

But you’ve seen those pressures at work - and been exposed to them (e.g. on watch, as OOD) - for a very long time before getting anywhere near command. So your ability to handle them is probably well understood by those who make promotion decisions.

As a result (and not surprisingly) the record shows extremely few examples of commanding officers truly unfit for the role, or broken down by it.

Anecdotal second-hand sea story follows, so take this with a grain of salt…

Back when I was in the Navy, I heard about this one submarine CO, who was not just a screamer (which wasn’t all that unusual), but also had a habit of pushing people forcefully up against bulkheads when he was unhappy with them (and he was always unhappy).

Anyway, word reached his superiors of this unacceptable behavior at the submarine squadron, so the squadron chief of staff (squadron second-in-command and a full O-6 Captain), was sent to ride along with the submarine for a two-week op. The submarine CO (an O-5 Commander), must have suspected that something was up, so he was on his best behavior.

However, just a few days before they were due to return, old habits reasserted themselves, and he started screaming at sailors again in the control room, culminating in him slamming a sailor up against the bulkhead right as the Chief of Staff entered the control room.

That was apparently enough for the Chief of Staff. He could have waited until the sub got back to port, but instead announced loudly, “Attention in Control, CMDR is hereby relieved of command of USS . CAPT hereby assumes command. Quartermaster of the Watch, record this in the ship’s log. CMDR , please confine yourself to your quarters.” After the (former) CO left the control room, the Chief of Staff made a similar announcement over the 1MC (shipwide announcing system).

When they got to port, the former CO quietly left the ship. The Chief of Staff was the temporary CO for a few weeks until a new CO was selected.

Anyway, this is the only situation in which I heard that a CO was actually relieved of command at sea for cause.

Usually when a CO screws up (such as running aground or a collision at sea), he is relieved of command upon returning to port. This actually happens surprisingly frequently. Not long ago, it seems like a month didn’t go by without a CO being relieved of command for cause.

I wonder if a CO ever used a medical pretext to relieve himself from command of a ship once he realized that he wasn’t up to the job, for instance in a combat situation? A medical doctor might collude by providing a weazly, yet formally correct and face-saving medical diagnosis, in the best interest of all parties.

Earlier threads on removals from command for screw-ups, some of which resulted in deaths:

Bumped with a slight tangent.

Just saw the very good 1965 movie The Hill starring Sean Connery, set in a British Army prison in the Libyan desert during WWII. Towards the end, the prison’s mild-mannered medical officer and the tough-as-nails senior NCO (who pretty much runs the prison since the CO is usually off-base spending time with his favorite whore) lock horns over how to handle the case of an injured prisoner.

The medical officer finally prevails, since it’s a medical decision as to proper care for the prisoner, but only after serious resistance from the senior NCO, who hates the prisoner and probably wouldn’t mind seeing him die.

In my tour of duty on an isolated USCG LORAN Station (Marcus Island, the white pearl of the Pacific), we had a BMC who quite literally went nuts. He was not the CO (an O-3 bid) or the XO (CWO2) but right below that, department head (three depts, all led by an E-7). Another ET and I went to the noon day meal near the end, and he was yelling and screaming at the mess cook over something. Someone brought in the MKC to try to calm him down. A few hors later I and other people are standing guard today over him with his arms and legs tied up, while the pecker checker (corpsman) is rummaging through things to sedate him. Finally got a USAF C-130 that was suppose to be returning to Guam to stop by, pick him up and fly him to USCG FESEC at Yokota AFB, Japan.
Major alcohol and boredom problems halfway through his tour. At first FESEC thought he was normal and was about the send him back to us on our weekly C130 supply run but he started flipping out again. Hmmm, let’s send him stateside to Walter Read hospital in Maryland. And let’s let him carry his health records, so when he reports there he can say he lost them and is there for some liver cirrhosis. Which he almost got away with until FESEC (Far East Section office) calls to check on him.

 The Commanding Officer of  Coast Guard  Group East Moriches that spearheaded the recovery of the TWA 800 flight 20 years got relieved pretty quick, apparently more for wanting the various groups there (lots. Huge operation) to leave quickly. I don't think it was medical and no one much spoke about it.  
 Of course that thing also featured some civilian getting on base and directing helicopters landings (badly) until a reservist noticed he had different insignia on his collar and 

sleeves than the day before.
On the other hand, one of the reserve officers got a quick promotion because he worked for the electric company and facilitated them getting generators and other items to handle the increased electric demand.

I would think this would be a situation in which it is in everybody’s interest to sweep it under the rug–not publicize it. The Navy doesn’t want it to be known it has mentally ill officers. The officer in question doesn’t want his reputation publicly damaged.

This seems a bit anachronistic IMO. In the modern (WW2 and later) military the mental health of the crew (including the senior officers) is obviously the responsibility of the ship’s doctor, as much as the physical health. I am not sure that would be the case at all in a Napoleonic era navy (when Hornblower is set). Ship’s surgeons were literal sawbones, the idea that they would weigh in on the mental heath of the captain seems pretty dubious to me.