I've used noodles as described above (mine has rod stock running all the way through them on one side of the noodle) but on really windy days the marker just blows off course unwinding the line even though the weight remains on the same spot on the bottom of the lake. A friend cut him out a couple using a 1 x 4 board notching the center out with a jigsaw. He then painted them flourescent orange. His seems to hold better on windy days although they sit flatter on the water making them a bit harder to see unless you're right on top of 'em.
Health nuts are going to feel stupid someday, lying in hospitals dying of nothing.