In this photo I am measuring the temperature of the elbow leading to my sea strainer. It tells me the Atlantic Ocean under my boat is 68 degrees and that the temp my raw water pump sees is 68 degrees.


Take this reading an save it to a Word doc. or just write it in a notebook. This is not a critical reading but nice to know each time you check. If the water temp was 32f then I would not expect the same temps elsewhere on the engine but if it's within 5-8 degrees all your other readings should fall in line.


Every spot I measure on my engine gets a number and a "dot" made with a Sharpie marker. I use the "dot" so I can get repeatability every time I aim the thermometer.


Please try to use roughly the same "aiming" distance when taking measurements and this will lead to more accurate readings.