thats a chum churn for attracting fish. hangs on the back of the boat. they dont make them anymore for some reason.
way cheaper to make your own anyways and very easy to make.....have 2 of them homemade that are about 50% bigger than the ones you can buy. Puts out a TON more chum than the commercial ones.
If you could post some more pictures, it would be appreciated. I've got a good idea of how one is made and was thinking of building my own also.
dont have any internal pics of it but def not hard. bent aluminum pipe, PVC as you can see, drill holes in caps to allow the pipe to slide up and down, springs help with shock but are not necessary though without them you will probably break caps occasionally, and a blade of some type attached to the pipe where it will be inside the PVC. I just cut some plate aluminum into diamond shapes and through bolted them to the AL pipe then bent the side out to make them cut a little bigger area. nothin to it.
Since you make your own equipment have you ever heard of this? I was floundering one time years ago and holding the Coleman lantern was a pain in the ass as well as the light reflects off the top of the water so its really not that easy to see the flounders buried in the sand. I saw a guy nearby who was catching the shit out of them. He had a length of PVC pipe that at one end he had attached a funnel. He had a waterproof 60 watt 12 volt light bulb with the screw end sticking into the funnel and the wires running out of the top of the PVC pipe and attached to a 12 volt motorcycle battery that he had in a backpack. He was able to put the whole funnel and bulb under water giving him a much better view of the bottom.
Actually I did make a floundering light similar to that but instead of the funnel and screw in bulb I made it with underwater LEDs and sealed it all. Lots commercially available ones like it now. Here is a link to one that is made in moss point ms that looks real close to how I made mine except I have my lights at 45s away from each other to give a broader spread of coverage. I only use it thought when it's a little windy I prefer a pan light when it's dead calm http://www.paddlepunks.com/mobile/Product.aspx?ProductCode=WH-001