So far I haven't had a bad experience with the dipsey hitting bottom and hanging-up. :shock: I've been running dipseys for over 15 years but it's probably just a matter of time, I'm due.
I've had them hit bottom 3 ways. One is when trolling close to structure, say over 120' bottom and the dipsey hits the wall of a steep drop off close by. Second was in a turn over,say 90' bottom and the inside dipsey hits. The third is when I do it on purpose to see the true depth my dipsey is running at for the conditions that I'm fishing.
In most cases the dipsey will ride the bottom if it's fairly smooth and you'll see the rod twitching like a small fish is on. If it hits something hard or digs in it will usually trip and start to surface. The dipsey doesn't nose into the bottom because it's usually at #2- 2 1/2 setting and the angle of the dipsey puts one side lower and that side hits first and slides along the bottom.
Never had any issues running dipseys with 4 downriggers. Biggest problem I have is fish hitting sliders on the riggers and getting into the dipsey wire. That's going to happen a few times a season. I just put up with it because both setups are just to good not to use.