Got to thinking about using a bobber for fishing for cats especially in river's. Someone on a catfish site mentioned using pop bottles. Well I got a hold of a 20oz bottle and one a bit smaller than half that. Put a small eye screw through the middle of the lid and used JB Weld to hold it there. Then got a can of spray foam and filled the bottles. Screwed on the caps and JB Welded them in place. Gonna give them a try on the John day for channels this coming year with hopefully a one oz weight under them. Figure on using then as slip bobbers. Hope this works! Hopefully will keep the bait off the bottom.