https://en.wikipedia.org/wiki/USS_Portland_(LPD-27)
Here is a rundown of
the Portland HYDRA shipboard trunked system:
USS Portland (LPD-27)
EDACS Wide-band
EDACS Wide-band
System ID – 003
397.2625 LCN-3
397.6125 LCN-5
397.7625 LCN-6
399.1625 LCN-7
399.3125 LCN-8
399.5625 LCN-9
399.7625 LCN-10
LCN-1 and LCN-2 were showing as part of the system, but were not active, so I could not confirm the frequencies. There was no LCN-4 showing.
Dockside security was using 395.2500, N293 and 398.6500,
N293 for simplex communications.
And one
item that came via “close-call” near field monitoring, a UHF air band beacon on 313.6250
MHz. It was a continuous AM carrier with Morse characters “A-I-A” being send
every 10 seconds. My assumption is since this vessel handles helicopters and
tilt-rotor aircraft, a navigation/homing beacon to the ship would be a must. But I was also told by a friend who spent time in the US Navy that all Navy vessels carry such beacons.