Prevent oil discharges from the bilge. Keep your engine well tuned to prevent fuel and oil leaks. Put an oil absorbent pad in your bilge and under your engine where drips may occur.
Spill proof your oil changes by using an oil change pump to transfer oil to a spill proof container. Wrap a plastic bag or absorbent pad around the oil filter to stop oil from spilling into the bilge.
When fueling prevent fuel spills by filling fuel tanks slowly and catching drips and spills with a rag. Don't "top off" your tank, leave it ten percent empty to allow fuel to expand as it warms.
Never use soap to to disperse fuel and oil spills.It is illegal and increases harm to the environment.
Save boat cleaning and repairs for the boat yard whenever possible. If you must work on the water, minimize your impact by containing waste. Use tarps and vacuum sanders.
Use only nontoxic antifouling paints. Remember dry storage reduces the need for paints and saves money.
Manage sewage waste properly. Never discharge sewage within three miles of shore. Use shore side facilities if you don't have an installed toilet.
Keep your trash on board until you reach land and it can be properly disposed of.
Reduce water pollution by using phosphate-free biogradegradable soap.
Sail or kayak!