1. Definition.—
In maritime law, collision is the impact of ship against ship, although usage is increasing the scope of the word so as to include contact with other floating bodies. It does not include stranding or running into structures forming a part of the land, such as bridges and wharves.
The question whether a collision is a subject for adjudication in admiralty is frequently one of some nicety. What constitutes a vessel within the meaning of admiralty jurisprudence has been discussed in Chapter 1, § 4.[20] While, in general, objects which come into collision must be afloat in the water to warrant recourse to the admiralty courts, and certainly must not be permanently attached to the shore, nevertheless the jurisdiction has been exercised when the collision was between a barge and a pier erected in the midst of a stream and unlawfully obstructing navigation. Atlee v. Union Packet Co., 21 Wall. (U. S.) 389. The jurisdiction has also been exercised where boats have come into collision with submerged and stranded wrecks and sunken articles.