I made my own using 1 gallon water jugs. You need a jug, an old fishing line spool, a 1/4" X 1 1/2" long stainless steel eye bolt, 2 washers, and 1 nylock nut for each buoy. Drill a 1/4" hole in the jug cap. apply silicone sealant to a washer and place it on the inside of the cap, it should be large enough to just fit inside. Apply some sealant to the line spool and place the line spool on the outside of the cap. Now add the other washer and thread the eye bolt through the assembly with the ring on the outside, add nut to the inside and tighten. I used bright green surveyors cord for line on my markers. Wind it on the spool and use lead sinker. Before deploying the marker, snap a glow stick and place it in the jug, replace the cap and toss it overboard. The glow stick will last for @ 8 hours.