(Sorry if this already exists. It should exist but I haven't been able to find it in an exhaustive ten minute search.)
This gizmo would be an after-market lever scale which attaches to the handle of any given fishing net.
Analog or digital, after clamping the scale anywhere on the net handle, most convenient for the type of boat and fish to be caught, simply dip the net into the water and set the scale to read zero with that much weight hanging from the fulcrum.
Next fish caught just rest the scale lip on the side of the gunwale and know exactly how much the fish weighs without needing to ram a hook into its gills after you take the hook out of its mouth.-- 2 fries shy of a happy meal, Jan 09 2019 Would the scale be adjustable to support fish stories?-- RayfordSteele, Jan 12 2019 Of course.For a small fee we can also enclose a set of tongs which are very realistic copies of The Donalds' tiny hands so that pictures of every catch will look absolutely yuge.-- 2 fries shy of a happy meal, Jan 12 2019 random, halfbakery