Hands-Off Fish Measurements

On The Fly Gear

January 2026

Article and photo by Polly Dean.

At the time I was introduced to this product I thought it was pretty cool! The more I thought about it, the more I realized that this is the perfect tool to estimate the weight and length of your catch, without additional handling of the fish, or even the need to take it out of your net. And, therefore, especially fly-anglers, but anyone that practice catch-and-release, would love to have such a tool on hand.

This small ball of about 1.5-inches in diameter, paired with an app that is downloaded onto your smartphone, will accurately measure the length, girth and weight of your fish in seconds. Manufactured by Fishtechy, it ensures an accurate measurement with no handling of your fish. The fish can be measured while still in your net.

You simply place the proof ball alongside your catch, being sure the ball is the same distance from your phone as the fish. Without bending the fish or capturing it at an angle, take a clear picture of it and let Fishtechy calculate the measurements and weight of it for you.

Apparently using the Proof Ball multiple times for measuring your fish, helps to improve its accuracy by “training” it to be more efficient. The more data it processes, the smarter it gets.

Fishtechy users also help a citizen science initiative by the collective data of real-time users that contribute in providing measurement and population fishery data. This device can actually help in enhancing fishery management without relying on invasive methods such as electrofishing.

This technology can also be used for tracking your catches without the requirement of manual keeping of logs. Fishtechy will automatically add every fish measurement of yours to a SMART Log.

Fishtechy offers advanced fish measurement features utilizing the Proof Ball.

Using the Proof Ball can be useful in tournament events. The app-camera along with the measurement technology can deliver accurate data that works perfectly with catch-and-release tournaments, live leader boards, verifying catches, or any support you can think of for your competition needs. It can transform the way anglers compete.