This is from the laws in Dana Point Harbor in Ca.
Sec. 2-2-163. Toilets and Refuse
(b) No person shall throw, discharge, deposit or leave or cause, suffer or permit to be thrown, discharged, deposited or left, either from the shore or from any pier or vessel or from any factory or elsewhere, any refuse matter of any description in the navigable waters of a harbor. (Code 1961, 22.111)
That would make it illegal to even wash your boat (forget about peeing over the side). Or am I missing something?