Eagle FishMark 480 troubles

[robertmee]

As indicated in another thread, I have a FishMark 480 that came with a Pontoon boat we bought. We don't really use it on the Pontoon so I'm going to move it to my Glasstream that I'm refurbing. The few times I have used it, I've noted a couple of things:

1) In water depths less than 4', the reading shows 1'.

2) Sometimes, after this, the display will stay at 1' even after moving into 20' water. After awhile it may come back, other times I get tired of waiting and doing a quick power cycle brings it right back reading correctly.

I'm wondering if it is possibly a bad transducer mounting location. It is mounted on the rear of one of the Pontoon which of course gets alot of turbulence. But, before I go to the trouble of unwiring, moving and rewiring this to the Glasstream, I'd like to know if it works.

Lastly, I believe it is using a skimmer transducer. I assume that a through the hull can be purchased for this unit? However, is that worth it considering I still have to breach the transom to get the temp sensor into the water? Maybe, mount the 480 w/ Temp to the trolling motor using the skimmer transducer and get something else for the helm?