Left,
The closet transducer would be the 526T-HDD. Just know with in-hull transducer installations there are so many variables with difference hull thicknesses we are unable to test them all. This means we are unable to attest to the accuracy of either of the ACCU-FISH and Bottom discrimination modes or how much the Rez-Boost feature will be affected.
Left,
If the sounders performance degrades with the increase to the vessels speed you most likely with a turbulence issue. The best way the verify this is to look for gaps in the sea floor as you increase speed, turbulence will affect the 50Khz side first then 200Khz. If you can, please post a screen shot of both frequencies going 0, 5 and 10 knots.
Left,
One other thing to check would be the fluid level. If the fluid is low, it just may be enough to cover the face of the transducer. As the vessel speed increases and the bow raises, this may expose the face of the transducer to an air gap.
