This thread has some good info: ClubGP Message Forum troubleshooting

The water temp runs right around 70F, so you more or less need a digital gauge to get an accurate read out. I have been thinking about doing something like that for my S2IC come next spring, if not then i'll likely go with a PLX gauge and sending unit that will read down to 32F. The only other gauge that I have found was a prosport that reads down to 50F.

w00t first post