I didn't see a mention to the type of bobber.
I fish brush piles and submerged trees all the time. There are several tips/tricks. I use slip bobber all the time. I put a lead weight about 12"-18" above my hook. IF I break off, its usually on the hook side of the weight, saving the bobber. If your constantly getting hung up, fish shallower so your hook is above whatever is snagging your hook. I also use a two set ups.
4 lb mono line with a #6 aberden hook. or
6lb mono line with a #4 aberden hook.
Most of the time, I will pull the hook straight before breaking the line. If I do break off, usually its below the weight.
There is a method to break off, reel up as much slack as you can, grab the pole and line and pull to one side or the other. IF the hook breaks free you want it flying past you and not straight at you. Beware where the line will go, into the tree behind you will be worse than the tree in the water.
HOI Crappie Club
Where family and friends come to compete for a little more than bragging rights.
Quick, someone teach me how to fish so I can win this tournament!!!