s ceased, and it may be a navigable waterway for only part
of its course. Although this doctrine was announced as an interpretation
of the commerce clause, the Garnett case and the decision rendered in
Southern S.S. Co. _v._ National Labor Relations Board,[374] to the
effect that admiralty jurisdiction includes all navigable waters within
the country, makes it applicable also to the admiralty and maritime
clause.

ADMIRALTY JURISDICTION VERSUS STATE POWER

The extension of the admiralty and maritime jurisdiction to navigable
waters within a State does not, however, of its own force include
general or political powers of government. Thus in the absence of
legislation by Congress, the States through their courts may punish
offenses upon their navigable waters and upon the sea within one marine
league of the shore. In United States _v._ Bevans[375] the Court denied
the jurisdiction of a federal circuit court to try defendant for a
murder committed in Boston Harbor in the absence of statutory
authorization of trials in federal courts for offenses committed within
the jurisdiction of a State. While admitting that Congress may pass all
laws which are necessary and proper for giving complete effect to
admiralty jurisdiction, Chief Justice Marshall at the same time declared
that "the general jurisdiction over the place, subject to this grant of
power, adheres to the territory, as a portion of sovereignty not yet
given away. The residuary powers of legislation are still in
Massachusetts."[376]

Exclusiveness of the Jurisdiction

Determination of the bounds of admiralty jurisdiction is a judicial
function, and "no State law can enlarge it, nor can an act of Congress
or a rule of court make it broader than the judicial power may
determine to be its true limits."[377] Nor is the jurisdiction
self-executing. It can only be exercised under acts of Congress vesting
it in the federal courts.[378] The admiralty jurisdiction of the federal
courts was made exclusive of State court jurisdiction by the Judiciary
Act of 1789 according to The "Moses Taylor,"[379] which also held that
State laws conferring remedies _in rem_ could only be enforced in the
federal courts. Consequently, the State courts were deprived of
jurisdiction of a great number of cases arising out of maritime
contracts and torts over which they had exercised jurisdiction prior to
1866. However, as before noted, the ninth section of the act of 1789
contained a provi