Going Rogue? Unlikely

 Someone posed the question online, as to the likelihood of a Navy ship’s captain going rogue. I speculated that it is an unlikely scenario, for the following reasons:

My experience is onboard civilian-operated supply ships for the US Navy. The Captain and other department heads have spent years fully indoctrinated in the Navy way of thinking. From the moment they are hired as Third Officers, they are given extensive training on various tactical and leadership topics. (In contrast, many engineering officers pay for 100% of their own training). Small amounts of responsibility, such as handling small arms or being the Flight Deck Officer, are given early, but can be revoked. That would be a red flag. The Admiral must personally approve promotions of civilian Captains. The more unconventional officers (pacificists, conspiracy theorists) are not placed on critical ships, such as the ammo carriers. And yes, Special Forces practice on how to get from the helicopter deck to the ship’s bridge.

On a combatant ship, as OP notes, all of these precautions, and more, would be utilized very rigorously in the selection of COs and XOs.

Has it happened in recent times? Yes. The privately-managed SS Columbia Eagle was taken over by entry-level crewmembers in a 1970 munity, as protest against the war in Vietnam. As far as government vessels go, the aforementioned measures are an insurance policy against barratry (by a ship's captain) and mutiny (by the crew). 

Wither the Radio Officer?

 

The Radio Officer is one of the shipboard positions no longer found anymore. The responsibilities for that position were shifted to the Deck Officer, and in a bygone era, the Deck Officers would split the Radio Officer’s pay. The Radio Officer was a member of the Deck department, but on government ships that still retain the position, they usually report to the engineering department. 

The Radio Officer was most famous for being an operator of the radiotelegraph, and later, the teletype. But their weight in gold was their ability to tune and maintain equipment.

Most maritime regulation is made on the basis of safety, not convenience of crewmembers. By 1979, satellite-based GMDSS (Global Maritime Distress Signaling System) replaced morse code as the primary method of distress communications on the high seas.

Crucially, modular components- with spare parts carried onboard, and shore-based servicing available in every port, meant that ship’s officers no longer had the maintainer role, just the operator role. By this point, radio officers were helping the Captain with various paperwork responsibilities: there wasn’t much for “Sparky” to do with reliable, self-adjusting equipment.

The US Coast Guard still offers Radio Officer licensure. A closer look at the requirements, such as telegraphy, reveals that this licensure is designed for legacy ships, including some on the Great Lakes, and the WWII-era museum ships. More relevant are the modern-day endorsements for licensed Deck officers, including GMDSS training, a two-week course.