Looking for ideas for 2003

[huisende]

If you took the Secchi Disk under water, and had two divers swim away from each other, one holding the disk, the other hodling the tape meassure, you sould get a visibility reading, instead of Water clarity. Water clarity can be skewed by reflections on the water. I think you can see farther under water than you can from above the water. maybe we should all carry a disk made of steal, then we could wear less weights on our belt.