I bought a stream thermometer:

[AndyS]

.......at my local sporting goods for $9.00.

I bought it to further enhance my logbooks by keeping water temps when I go fishing. Not only that I will be tracking the water temps in the lower Raritan river this summer because I am still amazed about the 5" brown trout we got in the seine net in South Bound Brook. Water temp today in Manville was a cool 64*
I think a good investment all around, one thing I really haven't looked into much is water temp.

[GetANet]

I have one that I got in a pet store, I primarily use it in the spring time late feb/march to check temp for bass fishing and have one on the fish finder. Def think it's a valuable thing to have in the arsenal.....

[surfrod]

Andy... about time :D

[Fishon1982]

Great investment I believe that know the water temp and wind are the most important thing about I have the fish hawk td for when I trout fish so I can know where to start trolling

[NJ219bands]

I have been using water temperature gauges for many years. I bought 2 William Joseph infrared thermometers a few years ago and after I replaced the battery, both thermometers didn't work properly. I use an old stream thermometer now and learned a lot about water temperature. The last flood caused the water temp to drop from 82 to 66 degrees. In the fall, winter and spring, the fish stop biting when the water temperature drops, but in the summer, the fish bite on dropping water temperatures.

[Capt. Lou]

.......at my local sporting goods for $9.00.

I bought it to further enhance my logbooks by keeping water temps when I go fishing. Not only that I will be tracking the water temps in the lower Raritan river this summer because I am still amazed about the 5" brown trout we got in the seine net in South Bound Brook. Water temp today in Manville was a cool 64*
I think a good investment all around, one thing I really haven't looked into much is water temp.

Check it against a lab thermo, sometimes not always those may be off a couple of degrees ! Also note how long it takes to arrive at temp reading , so u
get it right !
If ur a lake troller than u can't beat a good down temp gauge device to catch consistently!