What is "fleet captains"

Usage examples of "fleet captains".

We had come a long way since then, but I imagined that some fleet captains back home still bit their nails to the quick for every starship they sent into the void.

In the vast and deep dark of the Beyond, the negative couldn't be proven, and a destroyed ship, given the legendary canniness of the Fleet captains, was a wait-see, almost never a certainty.

Brutus, who had tied himself to the stem post of the ship so that the seas would not sweep him overboard, screamed at the oarsmenas within every one of the hundred ships in his fleet captains and officers screamed at oarsmento dig in and stabilize the chaotic spinning of the ships.

Don't you know that none except the fleet captains and officers and the king's high officials may ever leave here?

Flustered controllers were still trying to contact the Liberty, while fleet captains ran from screen to port, shouting, directing, misdirecting.