does a starfleet ship always have a CO with the rank of captain?

Although Tapestry indicates Picard was not captain when he started serving aboard the Stargazer. When describing Picard's alternate life, Q said "this Picard never took command of the Stargazer's bridge when its captain was incapacitated." Likewise, Conspiracy implies Picard was young when he was promoted to captain, since Walker Keel claims Tryla Scott beat Picard's record for how fast it took to make Captain.

So, the circumstances depicted in the novels pretty much fits everything we know from the show.

 

^ I always thought that Picard was a LCDR when he was promoted, and he just went straight to Captain. He skipped only one rank, not like nuKirk who skipped two.

 

there have been a few admirals commanding starfleet,in all good things admiral riker had the Enterprise D as his flagship.

 

That movie did have excellent research and got that right. At that time, operating task forces were organized as needed under an available admiral; Newton's normal "type" command was a cruiser division. Lexington's carrier division commander was RAdm Aubrey Fitch, who was returning to Pearl in Saratoga after a refit. As the war got going, the task force organization became the standard for operating forces, and the "type" chain of command became strictly administrative and shore-based.

I don't know how much you want to get into the esoterica of fleet organization, but below is how the "big ships" of the Pacific Fleet were organized in late 1941. Note only one of the four full admirals is there, the others were the CNO in Washington and the Atlantic and Asiatic Fleet CinCs. But all three vice admirals were in the Pacific Fleet:

In the English-speaking world, the rank of commander came about to distinguish captains of big ships from captains of small ships. Originally it was "captain (not taking post)" which implied that the officer was captain of a small vessel and was not entitled to be posted to the list of officers who would be promoted, by seniority, to rear admiral. By the late 1700s the rank had become "captain and master" and finally "master and commander," and differentiated the captain of a sloop from those of larger vessels. The title implied that the vessel was too small to have an assigned master (navigating officer), and the captain was expected to cover that duty himself. In the 1790s it was shortened to "commander." The US Navy had a similar rank of "master commandant." It too became just "commander" in the 1830s, but in practice the shorter title had been in use for some time.

Naval captains were never owners of vessels, they were originally military (army) officers who commanded the soldiers who "militarized" a merchant vessel. The owner was represented by the vessel's master, which is still the official term for a merchant captain.

 

Another nitpick: Keel only implies Scott beat the record of somebody present; the choices available are Keel himself, Picard, and Rixx. And Keel sort of looks at Rixx when saying this.

Timo Saloniemi

 

^ Actually, it was Picard who points this out. He says that Tryla Scott made Captain faster than anyone in Starfleet history, present company included.

 

Right; it's Picard who casts a look at Rixx at that point. Although it's probably more in reaction to Rixx holding him at gunpoint...

The "present company included" thing would be a bit odd for Picard to say if he himself were the one holding the current record. OTOH, it would be silly of him to say such a thing if one of the three weren't the previous record holder. Whether Picard is speaking of Scott making CO of a starship or reaching Captain rank, it's difficult to tell, as she is currently flaunting both qualifications. But we have seen hints that "specialists" like academicians might still enjoy an advantage in the rank race, with medical doctors perhaps graduating at a rank above Ensign; a redshirt like Scott would be at a disadvantage in the latter sort of competition, then.

Timo Saloniemi

 

Whilst I agree it is likely that in ST, Admirals don't normally command ship. Promotion doesn't have to automatically mean rank. It could mean a positional promotion. i.e your rank remains the same it's just that you are moved into a higher profile role.

Say as a Captain you where commanding an older class vessel, and you where given command of bigger newer vessel. You might consider it a promotion of sorts.

Starfleet could spina good PR story, Admiral Kirk who has just saved Earth has been given command of the refit Enterprise and been dispatched on a new five year mission.

Five years later, Admiral Kirk has ust returned succesfully from another five year mission, in his new positionas Commondant of Starfleet Academy he will help shape a new generation of officers.