Have any of you used this style of floating colony trap. I found them on YouTube and made a 7” and a 6” today. They have 12” deep tanks below water and a corrugated plastic door that will float up to cover the opening between the two sections. And a small hinged door in the lower section remove caught rats.

There’s a small lake a few miles away. I will run down there this week to see how they float.

I’ve used lots of floats for foot traps but haven’t done much with colony traps and never have used floating colony traps.

Yep, there was a discussion about these a few months ago. They've got their place. Way more bang for the buck loading the truck box with floats/footholds.
I've got mine stashed in the bush near a spot I can use it.

I’m really close to the Washington border and may trap some of my old stomping grounds. Cage/colony are my only options since they outlawed foot traps and body grips in 2000.

There are a couple of locations in the back sloughs and marshes where the "bottom" is hard to define. It might look all of 10" deep, but you can stick a paddle down into it and still not hit something solid. Yet there are distinct 'rat runs through this judging by the clean trails on top of this soft bottom. If you were to set a colony trap in this "run", it would sink and disappear into the goo below.

So I've been tinkering with a floating colony trap design. A typical 24" collapsible colony trap is attached to the underside of a board backed with styrofoam. The ends of the board have holes for sticks to go into and protrude upwards (not into the water) to cause the 'rat or mink to submerge and swim below it, still in the run, and into the colony trap. The colony trap is suspended just above the top of the sediment below, yet fully submerged. So far so good. Everything falls within the regs, so far.

Any other tinkerers out there with this application in mind?