We just installed a single site trunked system using 800MHz Kenwood NexEdge and I'm very pleased with the system performance. The audio does sound different than analog, that's for sure. There are a few adjustments in the programming software to play with the audio side of things, and you can tweak it for different external mics, AGC, low cut, different frequency response patterns, etc.
No issues at all with using digital at sea. The NXDN protocol will work fine on simplex, conventional digital repeaters or digital trunked systems.
Most large cruise ships have an internal repeater system, often with "leaky coaxial" systems to aid with coverage well below decks. NIce part about the newer digital systems is they often have Ethernet jacks on the repeaters that you can use to link systems.
There are standard UHF frequencies used worldwide by ships. It's pretty common to see these UHF frequencies in use aboard larger ships.
The Kenwood NXDN/NexEdge digital radios will do 25KHz and 12.5KHz analog FM, 12.5KHz or 6.25KHz NXDN Digital. I'm using 12.5KHz digital on the trunked system, and 12.5 analog for a back up repeater and simplex channel all in the same radio. I know you didn't ask about that, but it is possible to run both Analog and Digital out of these radios. Makes it easy to compare audio quality.
Last edited by mmckenna; 04-13-2012 at 12:29 PM..