Hi,
Many thanks for your response, the transducer is mounted mid ship through the hull on a Beneteau Antares 6 which has an inboard engine. The unit itself is flush mounted in the dash, there is other items of electronics around it (chain counter, fuel gauge, trim tab controls).
Unfortunately I dont have any screen shots from the unit itself, so I will have to get some next time I am out which will probably be at the end of the week, so I will post them then.
The message that I am getting from Humviewer is as shown in the link in my initial post (humviewer 3) basically it says "possible illegal data" "something seems to be wrong with B000, Should contain data for ...... seconds but instead it contains data for only ........ Please note that other data may be corrupt.
Thanks