Extends the time period during which both the Environmental Protection Agency (EPA) and any state with a state permit program are prohibited from requiring a National Pollutant Discharge Elimination System permit under the Federal Water Pollution Control Act (commonly known as the Clean Water Act) for a vessel that is less than 79 feet in length or a fishing vessel for any discharge: (1) of effluent from properly functioning marine engines, or of laundry, shower, and galley sink wastes; or (2) that is incidental to the normal operation of those vessels. Ends the prohibition on December 18, 2015, instead of December 18, 2014.

(This prohibition does not apply with respect to garbage discharged overboard, other discharges when the vessel is operating in a capacity other than as a means of transportation, ballast water [water held in ships to increase stability] discharges, or any discharge that contributes to a violation of a water quality standard or poses an unacceptable risk to human health or the environment.)