A COLAC (Commanding Officer, Light Attack Craft) is the Commanding Officer of the contingent of Light Attack Craft (LACs) aboard a LAC Carrier (CLAC).
The COLAC oversaw the LACs from the Primary Flight Operations center aboard the CLAC when not in battle. During a battle their place was with the LAC Wing onboard their own command LAC.
The COLAC commanded the LACS from a LAC in the formation because even with the FTL gravitics communications, the distance that LACs operate from their carriers would make the communication lag too great to tactically command in real-time.
The complement of LACs aboard a CLAC (usually 80-100 LACs) is known as a LAC Wing, and the wing will be designated by the carrier's Hull Number. (eg the LAC Wing carried by HMS Cyclops (CLAC-11) would be designated LAC Wing 11, or "Eleventh LAC Wing.")
The rank of a COLAC is typically Captain, which is also the rank of the Commanding Officer of the carrier, but the COLAC is not in the command structure of the carrier.
COLAC in TRMN
in The Royal Manticoran Navy: The Official Honor Harrington Fan Association, Inc. (TRMN), a COLAC is required for any fleet operating LACs. The COLAC will have a minimum rank of O-5, but can be an O-6. If there are no CLACs in the fleet, the LACs will be organized into a LAC Group.
If a fleet has carriers (CLACs), then LAC chapters may be part of the carrier's wing. A CLAC chapter in TRMN may have a COLAC even if there are no LAC chapters associated with the CLAC, but must have a COLAC if there are LACs reporting to the CLAC (ie assigned to the carrier's LAC wing).