On Wednesday, May 29, 2013 4:22:14 PM UTC+8, Bil wrote:
Make a Secchi Disk, download the app to your smartphone, take readings, and when in a port with connectivity, upload your results.

See:

http://www1.plymouth.ac.uk/marine/se...s/default.aspx

and

http://www.oceannavigator.com/Web-Exclusives-2013/Voyagers-join-the-ranks-of-marine-biologists/

or

http://www.pnas.org/content/110/18/7107.full