For the purposes of this chapter:

(1) “Derelict vessel” means any vessel, scow, lighter or similar floating structure or part thereof, whether or not moored, anchored or made fast to shore, that is broken or altered to such an extent that it will not keep afloat with ordinary care;

(2) “Harbor” means a place on navigable waters, as defined by this section, where water-borne commercial or recreational traffic enters for the purpose of anchorage or docking or the unloading or receiving of cargo, supplies, equipment, fuel or passengers;

(3) “Navigable waters” means waters which are subject to the ebb and flow of the tide shoreward to their mean high-water mark;

(4) “Navigable waterways” means waters which are physically capable of supporting water-borne traffic, and subject to the ebb and flow of the tide.