ship to dock and ship to ship; and it was connected to the dock with cables, utility lines, and a ramp. Id., at 21. At the same time, it was capable of being towed. And it was towed each winter to a harbor to avoid river ice. Id., at 20–21. The Court reasoned that, despite the annual movement under tow, the wharfboat “was not used to carry freight from one place to another,” nor did it “encounter perils of navigation to which craft used for transportation are exposed.” Id., at 22. (See Appendix, infra, for photograph of a period wharfboat).
The Court’s reasoning in Stewart also supports our conclusion. We there considered the application of the statutory definition to a dredge. 543 U.S., at 494. The dredge was “a massive floating platform” from which a suspended clamshell bucket would “remov[e] silt from the ocean floor,” depositing it “onto one of two scows” floating alongside the dredge. Id., at 484. Like more traditional “seagoing vessels,” the dredge had, e.g., “a captain and crew, navigational lights, ballast tanks, and a crew dining area.” Ibid. Unlike more ordinary vessels, it could navigate only by “manipulating its anchors and cables” or by being towed. Ibid. Nonetheless it did move. In fact it moved over water “every couple of hours.” Id., at 485.
We held that the dredge was a “vessel.” We wrote that §3’s definition “merely codified the meaning that the term ‘vessel’ had acquired in general maritime law.” Id., at 490. We added that the question of the “watercraft’s use ‘as a means of transportation on water’ is ... practical,” and not “merely ... theoretical.” Id., at 496. And we pointed to cases holding that dredges ordinarily “served a waterborne transportation function,” namely that “in performing their work they carried machinery, equipment, and crew over water.” Id., at 491–492 (citing, e.g., Butler v. Ellis, 45 F.2d 951, 955 (CA4 1930)).
As the Court of Appeals pointed out, in Stewart we also wrote that §3 “does not require that a watercraft be used
