Depth Finder loses bottom when > 150'

[Chuck - Raymarine - Moderator]

Welcome to the Raymarine Forum pcasterlin,

Q1. I think the transducer is the SS270, but may be the B258 or B260 (how do I tell?
A1. Please click here to view a FAQ addressing this subject.

Q2. The depth finder works great and is very good at finding bait and identifying fish and works for water temp. too. The problem is that once I get out past 150' or so deep, it stops finding the bottom. It intermittently gets readings up to about 200' and it will freeze at those for a few seconds, but ultimately just shows --.- for depth. I can manually adjust it and still identify targets in the water column down to about 150' but I don't get anything below that. After being out in deeper water and heading back in, it starts reading again in the low 200's intermittently and at 150' or so it begins working like it should again.
A2. It is possible that the Fishfinder application has been configured for the 200kHz-Only frequency. It is recommended that the system be tested in deep water with the frequency setting configured to auto and then 50kHz-Only. Should neither of these support bottom acquisition, then it is possible that the 50kHz circuitry of the DSM300 or transducer has failed. This problem would typically be troubleshooted in the field by temporarily connecting another compatible transducer (suspended over the side of the boat or place atop a ZipLock bag placed inside the hull (only for solid fiberglass hulls less than 1" thick) while the boat is drifting or at anchor. Alternatively, the DSM300 may be sent to Raymarine’s Product Repair Center to be bench tested/serviced.