Water Tempature Gauge running oddly low....

anyone have any reason this might be? btw, its 2003 Sea Ray I/O. It sorta came out of nowhere, we noticed the engine running a tad rough, and the tacometer has been sticking (about 2000RPM's higher than normal), but its been running well enough for us to use the boat normally and ride. Any reason the water tempature gauge is running abnormally low?

Might have the thermostat stuck open some. Water temp would be low and the engine would be rough and idle higher because it was cold. Try replacing that.
It could also be a ground fault in the dash wiring. look under the dash and check for loose or corroded wires.

I would think Art is right in that your thermostat is likely stuck open.

I haven't run a stat in a couple years... always 160*. I don't think that's it, but Art is an engine ninja and generally correct with his diagnosis... but I guess for the fun of it I'll throw mine in as well.

I would say the ground under the dash is loose since you have the tach doin its thing.... but the temp gauge is one wire and wouldn't be affected....... hmmmmm... I'm stumped.

ill check the thermostat and the wiring behind the dash, thanks for the help.