To quote the Library Data from 'Trail of the Sky Raiders':
"...the League's primary interstellar enforcement arm is the League Survey Service, a scout organization with military appendages. Most bases except that on Kokkelen are strictly Scout operations centers. Kokkelen base home to the LSS naval arm..."
That suggests something more like the USCG than the USN, I suspect at least some of the mobilization the League has been doing is up-arming ships normally used for survey work.
And her is a Jump 4 map showing just why the naval base was on Kokkelen, everything in the Domain of Alntzar can be reached from there by Jump 4 capable ships.