From an email posted to Baen's Bar BuShips dated June 7, 2005:

Coast Guard equivalent

    The question has been raised of just how much of the traditional "Coast Guard" role the Astro Control Service fills in the Star Kingdom of Manticore. If there isn't a Coast Guard analog, will there be one?

     

    Astro Control is as close as the Star Kingdom has to an equivalent of the Coast Guard. Astro Control's function is primarily civilian and/or law enforcement-oriented. It's responsible for traffic control throughout the entire volume of the star system in which it operates, and it operates a small fleet of rescue and emergency craft which would take the lead in dealing with most in-flight emergencies. At the time of On Basilisk Station, Basilisk ACS was operating in a star system whose exact status was… ambiguous. Under the terms of the special legislation covering Basilisk at that point, it was specifically the Navy's responsibility to provide the enforcement support ACS required (and which was not forthcoming until Honor arrived on the station). That situation no longer obtains, and Basilisk ACS now has its own armed pinnaces which serve the same relative function as the Coast Guard's cutters. Note, however, that those pinnaces are normally attached to ACS and crewed by regular Navy personnel. Also, ACS has no responsibility for the Junction forts were for the LACs and regular warships tasked to defend the Junction; although ACS coordinates with the Navy, the defensive plans and hardware to implement them are strictly the Navy's responsibility. As a consequence of all of the above, ACS has no units which could fulfill the equivalent role of the Coast Guard cutters which served as deep-ocean escorts during World War I. Commerce protection is entirely the responsibility of the Royal Manticoran Navy, which has a great deal of practice providing it.