I just bought a helix 5 di gps and a helix 7 si gps.
upon using for the first time the depths were alternating between 300 and 900 feet in 6 foot of water with 2 feet of weeds on both units.

after lifting both units out of the water and putting back in the Helix 7 started to work normally.

i have the helix 7 mounted on "DA Ducer" and the helix 5 on my trolling motor.
the helix 5 will only read right occasionally if i take the transducer and wipe it with a clean cloth then put it back in the water.

after a short (5 to 10 minutes) while ,the helix 5 starts to show 300 to 900 feet deep again.

i have had a 597 di on my trolling motor for years and never experience this before. the main reason i bought the helix di gps is my old unit gps stopped working.

Is there a setting that i need to adjust or is something wrong with the helix 5 or the transducer?

the helix 7 seems to work fine.