Suspect Depth Reading with C120W/DSM30/SS60

[Chuck - Raymarine - Moderator]

Welcome to the Raymarine Forum TideRace,



A1. Could this be a software (update) issue for the C120W and/or DSM30?
A1) No.

Q2. Is there a calibration function for the DSM30?
A2. Unless one has applied a waterline offset (positive depth offset value indicative of the depth of each transducer below the waterline) and tide accounted for, then comparisons should neither be made between the fishfinders nor to spot soundings. The Fishfinder application's menu includes a Fishfinder Set-up menu from which a Transducer Settings menu may be selected. The latter menu includes a Depth Offset feature which may be used to adjust the reported depths to equal one another. I suspect that these transducers are also both of tilted element designs rather than the 0 degree versions of these transducers. Should these transducer not be perfectly aligned with one another, then the beam of the transmitted energy from one or possibly both of the transducers may not be directed straight downward. This may also occur when the boat is rolling and the transducers are installed on opposite sides of the keel. Should you desire to have them equal one another, then the Depth Offset feature may be used to do so. However, I do not suspect that you will find the difference to be so great when operating in shallow water.

Q3. Is there an Operation Manual for the DSM30 (I haven't been able to find one)? There are many features and settings that I may want or need to explore or adjust but I'm not finding it intuitively obvious to do so without a manual.
A3. Raymarine only produced installation documentation for the DSM30/300. The fishfinder features supported by the DSM30/300 are documented within Chapter 12 - Using the Fishfinder of the C-Series Widescreen MFD User Reference Handbook.