Lake water temp sensor replacement?

[stonelx]

Anyone with an early 2000 Malibu that had issues with the lake water temp not showing correct temperatures?
My 2003 SunsetterLXI is showing the lake temp in the digital display as around 100 to 150 F. Obviously not correct.
Could this be the sensor?
I have a paddlewheel and a depth sensor, but then I have this weird thing, (which I think is the water temp sensor).
I don't believe my water temp sensor is in the paddlewheel like other boats, but not 100% sure.
Sorry for the crappy dark picture. This is just to the bow side of my bilge pump and very close to the pilon.

It looks like two wires are set into a small hole in the hull, and then it looks epoxied to keep it water tight.
I remember seeing some kind of sensor under the hull that looks like a quarter size black plunger with a small tube on it.
I've always assumed this was the water temp sensor.
Anyway, any tips on how to fix the issue?
Can I replace just the part under the hull, or do I have to replace everything including new wires back to the dash?
Thanks.

[asnowman]

Our 05 was reading the same kind of temps. A new paddlewheel/temp sensor actually arrived today.  Ordered from Bakes with crew discount. 

I believe it plugs into the dash, but won't know for sure until later in the week.