[TG] [TG11] Axiom/RV-100 - Unclear image

[Tom - Raymarine - Moderator]

Hello Ian,

I don't see the files DS_Lines, FishvertBreak, FS_Down, Grass etc., but it's good to hear that the stutters have stopped with the dedicated battery.

Regarding the performance at speed, you seem to have both an aeration and noise problem. The increase in noise is very apparent from 5 knots upwards in the increasing clutter level in the water column, and at 10-12 knots the noise level is getting close to the signal level from the bottom echo (similar colours.)

From 12knots on you also have an aeration problem: increasingly common vertical gaps in and weakening of the bottom image as you increase speed, which together with the increasing noise level means that the sounder can no longer distinguish bottom from noise at 16 knots.
To address the aeration, I'd look at the location, height and angle of the transducer and see what's upstream of it and whether there's something that can be done to get it into cleaner water. Looking over the back whilst someone else drives the boat at ~16 knots may help identify a better spot/height/angle.

Re. the noise, your two images where you revved in neutral are interesting: the fact that the interference is present on only the Port side of the SideVision (or almost, anyway) would seem to imply that the noise source is acoustic directly from the engine rather than electrical noise through cabling for example. I say this because I'd expect noise from any other source other than engine sounds to affect both SV channels equally.
You could test that perhaps by waving a bit of ply, acrlic board or similar on the end of a boat-hook in between the transducer and engine in order to block some of the engine noise (nowhere near the prop of course); if you wave it in and out of the gap between the engine and transducer and see a drop in noise level when it's in place, at 5-7 knots or so, then you've found the cause and have some idea what to do to solve it. I'd be interested in the results there. I think there's a fair chance this will make a big improvement in performance at speed, although probably at the expense of SV performance in that direction.

Regards,
Tom