Originally Posted By: Camprunner
Just wondering in a navy battle group is an Admiral usually the highest rank? More than one? And what ship would he usually be on I assume the aircraft carrier? Also are subs part of a battle group or are they off on there own?
OK, so, back on topic...
The Navy typically organizes forces into "Strike Groups". The Carrier is the centerpiece of a Carrier Strike Group (CSG) and the Amphibious Assault Ship is the centerpiece of an Expeditionary Strike Group (ESG). Ship complement in the group depends on the available ships, but every CSG/ESG will have an Arleigh Burke and/or Ticonderoga ship (AEGIS) for air defense/surface warfare and ASW. Submarines are generally part of a CSG.
There are numbered/named CSGs and ESGs on each coast. Each is commanded by an Admiral. The admiral has a staff. Each will have a carrier/Amphib and other forces assigned as the mission requires. There is a strike group on each coast (CSG-4 on the East Coast, CSG-15 on the west) that trains/certifies other strike groups (and independently deploying ships) as ready for deployment.
The admiral is generally a 1-star (Rear Admiral lower half), but is often a 2-star (Rear Admiral). A CSG is a big step in a flag officer's career. They get selected to command one after successful performance in a 1-star job prior to the CSG/ESG, so they are often selected for the promotion just prior to taking command, or while in command, of the CSG/ESG.
The centerpiece ship (carrier or amphib) has the spaces and systems to support the Admiral and his staff. They're built that way. So, the admiral embarks on that ship and it is the "flagship" of the ESG/CSG.
In the days of fighting sail, the Admiral wouldn't have much of a staff, and would choose one of the ships of the line from which to command. So that all the other ships knew which ship to follow, the admiral's pennant (flag) would be flown as the highest signal flag on that ship. Hence, "flagship". Orders to other were given by flags flown below the admiral's pennant.
"England Expects Every Man Will Do His Duty" was flown from HMS Victory, Nelson's flagship, just prior to engaging the French at Trafalgar. Now, that was a set of orders, flow as signal flags, but it was superfluous. Nelson briefed his commanders the night before and each knew their commander's expectations and their roles in the upcoming fight. Nelson sent the orders via flag, knowing that they would be read aloud on every ship, to motivate his crews.
So, to this day, the admiral's ship is a "flagship" and officers above the rank of Captain are referred to as "Flag Officers".
Cheers,