Gives you the inshore forecast, shipping forecast, weather and navigational warnings in text format via an aerial mounted on your boat. Very useful indeed, but all information can be obtained via the internet.
I find it very useful in the Med because I dont know any other sources of english language forecasts there but in UK waters, there are so many other sources that I would'nt have thought it necessary. Nice to have though as the receivers are relatively cheap and the service is free
All very positive responces so far but be prepared for limited performance in Marinas which is where most of us do our planning. The transmitters are low power and lots of masts apparently reduce the signal significantly. A really good earth is important. I have found the Meteo France forcasts very reliable in the Med when I do get them.
You need to leave it on to receive the messages. I tend to turn everything off on the boat when I leave so when we get down on Saturday morning and turn the Navtex on, I have to wait until Sunday morning until there is anything useful.
I have linked my unit to the GPS so it shows only local info.