I recently bought a Hunter 30FT, and it came with a datamarine depth gauge and a Kenyon speedometer/ odometer. The odomoter is working but the speedometer is not. The speedometer spiked up to the GPS reading once. The depth gauge read 1 Foot when it was in the yard. It now reads 1 Foot at the mooring. IF I flick the off/dim/bright switch on the back of the unit I get a reading of 44ft at the mooring. This might be an anomaly because it is too deep for the mooring area. Can anyone help me with this, I would love to get them fixed.