For purposes of this chapter, the following definitions are applicable:

(1) "Commercial fishing vessels" means any vessel which is documented under the laws of the United States or, if under five net tons, registered under the laws of any state, and used for commercial fishing or activities directly related to commercial fishing.

(2) "National Oceanic and Atmospheric Administration (NOAA) research and survey vessels" means NOAA vessels used for research and survey purposes.

(3) "No Discharge Zone" means an area where federal approval has been received to allow a state to completely prohibit the discharge from all vessels of any sewage whether treated or untreated.

(4) "Public vessels" means a vessel owned or bareboat chartered and operated by the United States, by a state or political subdivision thereof, or by a foreign nation, except when such vessel is engaged in commerce.

(5) "Small commercial passenger vessels," also referred to as "small cruise ships" are commercial passenger vessels that provide overnight accommodations for less than two hundred forty-nine overnight passengers for hire, determined with reference to the number of lower berths.

(6) "Sewage," also known as blackwater, means human body wastes and the wastes from toilets and other receptacles intended to receive or retain body wastes.

(7) "Tug boats,""towing vessel" or "tugboat" is a commercial vessel that is engaged in or intending to engage in pulling, pushing, hauling alongside, or a combination thereof.