Here you go Ian,
The rods are ten feet long, made of 1/2 fiberglass with a special exterior finish that is real hard, one end is ground to a point. Here is what the tops look like, with attached hardware.
With a trap attached.
With a snare attached.
Pointed end (Deep water end) with drowning lock stop.
Sorry this took so long Ian, but I had it written once and almost finished and hit the ctrl button somehow?????
Any way. LOL
The rods come white in color, sharpened on one end to a point, square cut on the other end. I make all the hardware and paint them black.
The top end, has a double loop for the stake, next piece down is the drowning lock. Loops on the top is where the stake goes to keep it anchored at the trap set location. I use T-bar stakes (30") because I have a better handhold and can twist them when pulling to break suction in mud. Each trap/snare has a piece of flat stock and cable attached to the snare/trap to make the connection from trap/snare to the drowning rod, and can be attached or detached easily and also gives the trap/snare another swivel point. Drowning rod has a stop screw in the rod to stop the drowning lock about a foot from the bottom.
In use, I find a location I want to set(dam break set, castor mound set, spot beaver is going to shore etc), I push the pointed end of the rod into the bottom in a minimum of three feet of water when set. The angle of the rod varies with angle of bottom and water depth at site. I want the bottom end to be pushed into mud at least a foot, so the beaver can't pull it out when it gets there. I push/ adjust the top end until it is about a foot from where I want to place my trap/snare, and under water when set and anchored. When the trap/snare is set, I put a T-bar stake through one loop at the top of the drowning rod and push it into the bottom until it just clears the bottom.
When the beaver realizes it is caught, it instinctively dives for deep water. The drowning lock is L-shaped and only allows the beaver to go down the rod to deeper water. If the beaver tries to go back to the bank or at a right angle to the rod, the drowning lock cams on the rod and won't allow the beaver to any direction but down, into deeper water, away from predators and into cooler water. The reason I want a minimum of three foot of water at the deep end is that a beaver caught by either front or rear foot can't get back to the surface to breath, unlike a long neck swan with a seven foot wing span. LOL Also works well for Otter, Mink, Nutria, and Muskrats.
Top picture is an early prototype, second pic is the updated version.