Maybe you should try more than one dive stick, I have used "substantial" sized dive sticks, and small ones. I picture a beaver waiting to dive till it is almost to the dive stick, is it going to go straight to the bottom, or just under that obstacle. I get them down on the bottom before the dive pole over trap. Besides, if you put one dive pole, why not two or three? Have you ever came to a spot where there was already these obstacles in the way? They are used to diving here and just a matter to slip a trap or two in place. Give them one dive pole over the trap and they may just remove it. Wire it in place, and they still try to remove it the whole time stopped and messing around the top of your submerged trap just asking for a sprung trap. As far as missing a few beaver, I don't settle for that or wait to catch them at the dam or den. These places are ready to catch the others before they have to much time to figure somethings not right. I never set at the den untill a last option, this will send off an alarm you don't want.