The federal admiralty jurisdiction being wholly independent of the power to regulate interstate commerce, and attaching whenever the cause of action has arisen on navigable water, jurisdiction extends over all cases arising upon navigable waters even though they be wholly within the confines of a particular State, provided they be connecting links in a chain of commercial communication between States. In The Daniel Ball4 the court say: "Those rivers must be regarded as public navigable rivers in law which are navigable in fact. And they are navigable in fact when they are so used, or are susceptible of being used, in their ordinary condition, as highways for commerce, over which trade and travel are or may be conducted in the customary modes of trade and travel on water. And they constitute navigable waters of the United States within the meaning of the acts of Congress in contradistinction from the navigable waters of the States, when they form in their ordinary condition by themselves, or by uniting with other waters, a continued highway over which commerce is or may be carried on with other States or foreign countries in the customary modes in which such commerce is conducted by water."

3 The Magnolia, 20 How. 296; 15 L. ed. 909.

4 10 Wall. 557; 19 L. ed. 999.

In The Montello5 the same principle was applied to the Fox river of Wisconsin, although its navigability was interrupted by rapids and falls around which portages had to be made.

Federal admiralty jurisdiction is not affected by the fact that at the time of the accruing of the cause of action the vessel or vessels concerned are upon a voyage between ports of the same State.6