[yandina]

How the dynaplate works.

The theory is that the porus surface of the dynaplate provides a very large surface area contact with the water - many times the area of the plate itself.

The truth is that the resistance of the seawater down through the crevices is so high in comparison to the copper to seawater interface that it doesn''t provide any added advantage over a plain copper plate of the same size.

I don''t imagine that green marine growth diminishes the effectiveness very much, although barnacles may have sufficient insulation to reduce the surface area.

I believe that Practical Sailor did a test on dynaplates and found them no more effective than an equivalent copper plate.

If you have a metal keel, even if enclosed in fiberglass, this is the best and easiest ground to use.