Depth Display erratic readings

[C Sail]

We have a similar problem with our sailboat depth display.

We have an i70 installed and networked with es98, p70, and iTC-5.
I've shut the depth alarms off because they're constantly sounding when coming into Point Loma and San Diego even though water is 50 feet deep and the alarm was set first for 14 ft, then 7ft, then 5ft. Sorry, don't know which model depth transducer we have. So far this doesn't appear to happen in water over 60 ft. The depth reading issue has begun since installing the new instruments in May.

Will watch thread for information - Thank you!