Boat Washing
According to the BoatUS Foundation, tests showed that the label "biodegradable" doesn't mean much when it comes to boat soaps.
Technically it means that the ingredients break down into harmless components when they go through typical wastewater treatment, but we know that likely won't happen with boat soaps. So while the label sounds nice, it doesn't mean much.
Also, the results of the Foundation's tests varied greatly: One soap labeled "biodegradable" can be hundreds of times less degradable than another with the exact same label.
When using boat soaps, those products that say "dilute with water in a bucket" are much less toxic than those products that are applied as a paste or a spray. When you have a troublesome spot, use one of the spray or paste cleaners, but wipe up with a rag instead of rinsing into the water.
The best general advice is to wash your boat on the hard, away from the water's edge.
If you must clean your boat in the water, we recommend frequent freshwater rinsing to minimize the buildup of dirt.