685.—(1) Where any district within which any court, justice of the peace, or other magistrate, has jurisdiction either under this Act or under any other Act or at common law for any purpose whatever is situate on the coast of any sea, or abutting on or projecting into any bay, channel, lake, river, or other navigable water, every such court, justice, or magistrate shall have jurisdiction over any vessel being on, or lying or passing off, that coast, or being in or near that bay, channel, lake, river, or navigable water, and over all persons on board that vessel or for the time being belonging thereto, in the same manner as if the vessel or persons were within the limits of the original jurisdiction of the court, justice, or magistrate.

(2) The jurisdiction under this section shall be in addition to and not in derogation of any jurisdiction or power of a court under the Summary Jurisdiction Acts.