[DG] [TG11] RV100 Axion 9 loosing bottom at speed

[Tom - Raymarine - Moderator]

Hello fish for fun,

Your system is working very well, for those speeds. The RV-3D will never work at high speed, that's normal and expected (it's not designed to, and can't do that level of signal processing on the messy, noisy signals that you inevitably get at high speeds), but your SV and Sonar channels are working very well considering the speed (personally I have never seen SV look as good as in your 50.4kph shot, at that kind of speed.)

You do have some pulsed noise in your Sonar channel that's very apparent in the 50.4kph shot (the vertical stripes/columns of much higher background clutter) and by carefully watching that screen whilst feeling/listening what's happening with the boat at the time you might be able to narrow down where that noise is coming from (for example, is it when the boat ploughs into the back of a wave) and maybe get the image even better. You can also improve the high-speed bottom-tracking by using an appropriate manual range setting, but if you consider that the transducer is a sensitive microphone and how much actual noise there is for it to pick up, in a 50kph water flow, mounted on a vibrating transom and close to a noisy outboard and prop, it's not at all surprising that it's giving a cluttered image. How much wind noise would your phone microphone pick up if you tried to make a call in the wind at that speed?

You definitely don't have a problem with your transducer height/angle from the point of view of aeration, and you definitely don't have a fault with your system, and if you can find where that pulsed noise is coming from you might be able to improve your high-speed performance from good to outstanding.

By the way, because of the angle of the view I can't see whether the RV image is normal at low speed, but I assume it would be based on the other images.

Regards,
Tom