What can be used as a bobber for a fishing line?

You want to try to determine the depth of the fish to determine where to set your bobber. If the sun is high up in the sky, the fish are generally looking at the bottom to eat. So you would want to try to get the bobber as close to the bottom as possible.

If the fish are cruising, usually in the mornings and evenings, you can set the bobber at about 4-5 feet. They are looking up and down for food, and are usually actively feeding around these times.

Once it gets cloudy out, you can usually put it about 1-2 feet above your hook. This will let the fish cruising by look up at your bait without getting blinded by the sun.