Sun Company ChillChek - Waterproof Thermometer with Breakaway Lanyard | Water Proof Temperature Gauge for Swimming, Diving, Snorkeling, Fishing, or Camping | Small Portable Outdoor Thermometer

Very accurate tool. It's compact size with no dependence on a battery system. Is a trusted temperature monitor for travel medication carry.

Temperature measurement marks are set at increments of 5. If you’re trying to measure something more specific this is not the thermometer for you. (I ended up needing to know temperature to the exact degree or two. I learned that certain fish will bite at 52°, but virtually disappear when the water temp measures 53°.) Good thermometer if you do not need specific temp (for example if the water is in the upper 50’s vs lower 60’s). Thermometer was waterproof and compact.

The good news is that it’s small. The bad news is that it is too small. You can only read temperatures with an accuracy of 5 degrees. That’s practically useless.

I bought this to attach to my float for cold water swimming. It works as advertised! As it is very small, and my eyes are over 50 years old, it's a little hard to read when you're bobbing out in the water, and because it is small the gradient is very chunky, so it's hard to tell if the water is 50, 51, 52, etc... but when the water is that cold, it doesn't matter that much! It's cold!

It didn’t work from the start-always read 80-never changed and was very hard to read. Non returnable item.

Small but works for water temp off my dock!

Easy to use, definitely water proof, compact and light for active people. 5 degree +- accuracy

About all I can tell about the temperature of the indoor pool I use for water aerobics is whether it's above 80° or below.