Save a few bucks on your marker buoys while helping keep your offshore honey hole a secret; Use your empty plastic water or coke bottles to make marker buoys. Simply tie on an appropriate amount of string and a weight, wrap it around the bottle, toss it out and watch it unwrap. When your buddies pass by they'll assume the marker buoy is just trash, or maybe a marker to a catfish line. I managed to keep a spot in the middle of the river channel a secret for several years using this technique. Be sure and pick them up when you're done for the day so they don't actually become litter.