So what's a slip bobber? Well, a slip bobber is a bobber that slides freely up and down your fishing line. For any bobber to work there must be a way to hold the bobber at a certain spot on the fishing line. To use the clip on type bobbers, you simply clip the bobber above the hook at the depth that you want your bait to be under water. This is fine but it limits your ability to cast. It also makes it extremely hard to fish any deeper than about 6 feet. Here's where the slip bobber out shines the clip on bobber. The slip bobber allows you to cast just about as far as you normally would. You can also fish as deep as you want. I have used slip bobbers to catch Crappie 30 feet deep in 40 feet of water.
Rigging up a slip bobber takes a little more time than using a clip on bobber but it's well worth the little bit of extra effort. Clip on bobbers have a clip to hold the line. Slip bobbers have a hole thru them so that they can slide up and down the fishing line. There is usually a small knot tied on the fishing line to stop the bobber from sliding up the line. The line used to tie the knot is usually made of string. I use dental floss. Next, a small bead with a hole thru the center is slid on to the line. The knot should be big enough to stop the bead from sliding past the knot, but small enough to pass through the rod guides easily. Now the bobber is slid on the line and the hook is tied to the end of the line. I usually place a slip shot on my line between my hook and the bobber. The split shot keeps the bobber off of the hook while casting.
You'll find that you will be able to use a slip bobber in a lot more situations than you could with the clip on bobber. You can use slip bobbers to precisely hold you bait just off the bottom no matter how deep the water is. Good luck!