I got an answer on THT, so I thought I would re-post here in case anyone was interested...
He had the chanels expanded....someone has to do a software update on the unit or something like that an you can get a lot more chanels, and if you buddy has a similar unit you can have super secret chanels to communicate on off shore.
The rest of the thread will proabbly be dedicated into the legality of using it...
Yes, it is illegal to use that channel on a marine VHF in the U.S. In other parts of the world, it is a legal marine channel. In the U.S., it is a land mobile channel. The frequency is 157.525 and may be used by land mobile stations such as police, fire, taxi's or other commercial services.
You can "open" individual channels or all of the expanded channels by using the field programming software for this radio. It is also illegal for end users to have this software as it is intended for dealers and licensed service tech's only.
Channel 90 is normally a duplex channel so either he was using channel 90A or the duplex function was turned off which you can also do with the software. I'm a licensed service tech and have this software.
Channel 90 is one of the commonly used expansion channels used by charter boats who want their conversations private.
I mention the legality of it, just so you know. It doesn't matter to me. If your not interfering with any land mobile units using the channel, there's no worry.
