Earlier this year I began a thread entitled "Anti Fouling Paint Manufacturers Taking Aim At Hull Cleaners." Maybe some of you remember it. Anyway, in that thread, I referenced a study of in-water hull cleaning's copper contribution to the water column. Not the first study of its kind, but the first one funded by the paint manufacturer's lobbying group. It was published a couple of weeks ago and as expected, the results show that copper-based anti fouling paint is much less of an issue than every other previous study has shown, and that in-water hull cleaning is much more of a problem. By a factor of 10. Where previous studies show that hull cleaning contributes about 5% of the copper that gets into the water from anti fouling paint, this study shows it to be about 50%. If you were ever in doubt about the meaning of the phrase, "The fox guarding the hen house," this scenario should clear that right up for you.
We don't know how the paint manufacturers will want the state to use this study, but we suspect it could be used to implement mandatory cleaning frequencies in California, and by that I mean much less frequent than the boat owner would like. FYI.