[119]*119MR. Justice Van Devanter
delivered the opinion of the Court.
These are suits by steamship companies operating passenger ships between United States ports and foreign ports to enjoin threatened application to them and their ships of certain provisions of the National Prohibition Act. The defendants are officers of the United States charged with the act’s enforcement. In the first ten cases the plaintiffs are foreign corporations and their ships are of foreign registry, while in the remaining two the plaintiffs are domestic corporations and their ships are of United States registry. All the ships have long carried and now carry, as part of their sea stores, intoxicating liquors intended to be sold or dispensed to their passengers and crews at meáis and otherwise for beverage purposes. Many of the passengers and crews are accustomed to using such beverages and insist that the ships carry and supply liquors for such purposes. By the laws of all the foreign ports at which the ships touch this is permitted and by the laws of some it is required. The liquors are purchased for the ships and taken on board in the foreign ports and are sold or dispensed in the course of all voyages, whether from or to those ports.
The administrative instructions dealing with the subject have varied since the National Prohibition Act went into effect. December 11, 1919, the following instructions were issued (T. D. 38218):
“All liquors which are prohibited importation, but which are properly listed as sea stores on vessels arriving in ports of the United States, should be placed under seal by the boarding officer and kept sealed during the entire time of the vessel’s stay in port, no part thereof to be removed from under seal for use by the crew at meals or for any other purpose.
“ Excessive or surplus liquor stores are no longer dutiable, being prohibited importation, but are subject to seizure and forfeiture.
[120]*120“ Liquors properly carried as sea stores may be returned to a foreign port on the vessel’s changing from the foreign to the coasting trade, or may be transferred under supervision of the customs officers from a vessel in foreign trade, delayed in port for any cause, to another vessel belonging to the same line or owner.”
January 27, 1920, the first paragraph of those instructions was changed (T. D. 38248) so as to read:
“All liquors which are prohibited importation, but which are properly listed as sea stores on American vessels arriving in ports of the United States, should be placed under seal by the boarding officer and kept sealed during the entire time of the vessel’s stay in port, no part thereof to be removed from under seal for use by the crew at meals or for any other purpose. All such liquors on foreign vessels should be sealed on arrival of the vessels in port, and such portions thereof released from seal as may be required from time to time for use by the officers and crew.”
October 6, 1922, the Attorney General, in answer to an inquiry by the Secretary of the Treasury, gave an opinion to the effect that the National Prohibition Act, construed in connection with the Eighteenth Amendment to the Constitution, makes it unlawful (a) for any ship, whether domestic or foreign, to bring into territorial waters of the United States, or to carry while within such waters, intoxicating liquors intended for beverage purposes/whether as sea stores or cargo, and (b) for any domestic ship even when without those waters to carry such liquors for such purposes either as cargo or sea stores. The President thereupon directed the preparation, promulgation and application of new instructions conforming to that construction of the act. Being advised of this and that under the new instructions the defendants would seize all liquors carried in contravention of the act as so construed and would proceed to sub[121]*121ject the plaintiffs and their ships to penalties provided in the act, the plaintiffs brought these suits.
The hearings in the District Court were on the bills or amended bills, motions to dismiss and answers, and there was a decree of dismissal on the merits in each suit. 284 Fed. 890; 285 Fed. 79. Direct appeals under Judicial Code, § 238, bring the cases here.
While the construction and application of the National Prohibition Act is the ultimate matter in controversy, the act. is so closely related to the Eighteenth Amendment, to enforce which it was enacted, that a right understanding of it involves an examination and interpretation of the Amendment. The first section of the latter declares, 40 Stat. 1050, 1941:
“ Section 1: After one year from the ratification of this article the manufacture, sale, or transportation of intoxicating liquors within, the importation thereof into, or the exportation thereof from the United States and all territory subject to the jurisdiction thereof for beverage purposes is hereby prohibited.”
These words, if taken in. their ordinary sense, are very plain. The articles - proscribed are intoxicating liquors for beverage purposes. The acts prohibited in respect of them are manufacture, sale and transportation within a designated field, importation into the same, and exportation therefrom. And the designated field is the United States and all territory subject to its jurisdiction. There is no controversy here as to what constitutes intoxicating liquors for beverage purposes; but opposing contentions are made respecting what is comprehended in the terms “ transportation,” “ importation ” and “ territory.”
Some of the contentions ascribe a technical meaning to the words “ transportation ” and “ importation.” We think they are to be taken in their ordinary sense, for it better comports with the object to be attained. In that [122]*122sense transportation comprehends any real carrying about or from one place to another. It is not essential that the carrying be for hire, or by one for another; nor that it be incidental to a transfer of the possession or title. If one carries in his own conveyance for his own purposes it is transportation no less than when a public carrier at the instance of a consignor carries and delivers to a consignee for a stipulated charge. See United States v. Simpson, 252 U. S. 465. Importation, in a like sense, consists in bringing an article into a country from the outside. If there be an actual bringing in it is importation regardless of the mode in which it is effected. Entry through a custom house is not of the essence of the act.
Various meanings are sought to be attributed to the term “ territory ” in the phrase “ the United States and all territory subject to the jurisdiction thereof.” We are of opinion that it means the regional areas — of land and adjacent waters — over which the United States claims and exercises dominion and control as a sovereign power. The immediate context and the purport of the entire section show that the term is used in a physical and not a metaphorical sense, — that it refers to areas or districts having fixity of location and recognized boundaries. See United States v. Bevans, 3 Wheat, 336, 390.
It now is settled in the United States and recognized elsewhere that the territory subject to its jurisdiction includes the land areas under its dominion and control, the ports, harbors, bays and other enclosed arms of the sea along its coast and a marginal belt of the sea extending from the coast line outward a marine league, or three geographic miles. Church v. Hubbart, 2 Cranch, 187, 234; The Ann, 1 Fed. Cas., p. 926; United States v. Smiley, 27 Fed. Cas., p. 1132; Manchester v. Massachusetts, 139 U. S. 240, 257-258; Louisiana v. Mississippi, 202 U. S. 1, 52; 1 Kent’s Com., 12th ed., *29; 1 Moore [123]*123International Law Digest, § 145; 1 Hyde International Law, §§ 141, 142, 154; Wilson International Law, 8th ed., § 54; Westlake International Law, 2d ed., p. 187, et seq; Wheaton International Law, 5th Eng. ed. (Phillipson), p. 282; 1 Oppenheim International Law, 3d ed., §§ 185-189, 252. This, we hold, is the territory which the Amendment designates as its field of operation; and the designation is not of a part of this territory but of “ all ” of it.
The defendants contend that the Amendment also covers domestic merchant ships outside the waters of the United States, whether on the high seas or in foreign waters. But it does not say so, and what it does say shows, as we have indicated, that it is confined to the physical territory of the United States. In support of their contention the defendants refer to the statement sometimes made that a merchant ship is a part of the territory of the country whose flag she flies. But this, as has been aptly observed, is a figure of speech, a metaphor. Scharrenberg v. Dollar S. S. Co., 245 U. S. 122, 127; In re Ross, 140 U. S. 453, 464; 1 Moore International Law Digest, § 174; Westlake International Law, 2d ed., p. 264; Hall International Law, 7th ed. (Higgins), § 76; Manning Law of Nations (Amos), p. 276; Piggott Nationality, Pt. II, p. 13. The jurisdiction which it is intended to describe arises out of the nationality of the ship, as established by her domicile, registry and use of the flag, and partakes more of the characteristics of personal than of territorial sovereignty. See The Hamilton, 207 U. S. 398, 403; American Banana Co. v. United Fruit Co., 213 U. S. 347, 355; 1 Oppenheim International Law, 3d ed., §§ 123-125, 128. It is chiefly applicable to ships on the high seas, where there is no territorial sovereign; and as respects ships in foreign territorial waters it has little application beyond what is affirmatively or tacitly permitted by the local sovereign. 2 Moore International [124]*124Law Digest, §§ 204, 205; Twiss Law of Nations, 2d ed., § 166; Woolsey International Law, 6th ed., § 58; 1 Op-penheim International Law, 3d ed., §§ 128, 146, 260.
The defendants further contend that the Amendment covers foreign merchant ships when within the territorial waters of the United States. Of course, if it were true that a ship is a part of the territory of the country whose flag she carries, the contention would fail. But, as that is a fiction, we think the contention is right.
A merchant ship of one country voluntarily entering the territorial limits of another subjects herself to the jurisdiction of the latter. The jurisdiction attaches in virtue of her presence, just as with other objects within those limits. During her stay she is entitled to the protection of the laws of that place and correlatively is bound to yield obedience to them. Of course, the local sovereign may out of considerations of public policy choose to forego the exertion of its jurisdiction or to exert the same in only a limited way, but this is a matter resting solely in its discretion. The rule, now generally recognized, is nowhere better stated than in The Exchange, 7 Cranch, 116, 136, 144, where Chief Justice Marshall, speaking for this Court, said:
“ The jurisdiction of the nation within its own territory is necessarily exclusive and absolute. It is susceptible of no limitation not imposed by itself. Any restriction upon it, deriving validity from an external source, would imply a diminution of its sovereignty to the extent of the restriction, and an investment of that sovereignty to the same extent in that power which could impose such restriction.
“All exceptions, therefore, to the full and complete power of a nation, within its own territories, must be traced up to the consent of the nation itself. They can flow from no other legitimate source.
[125]*125“ When private individuals of one nation spread themselves through another, as business or caprice may direct, mingling indiscriminately with the inhabitants of that other, or when merchant vessels enter for the purposes of trade, it would be obviously inconvenient and dangerous to society, and would subject the laws to continual infraction, and the government to degradation, if such individuals or merchants did not owe temporary and local allegiance, and were not amenable to the jurisdiction of the country. Nor can the foreign sovereign have any motive for wishing such exemption. His subjects thus passing into foreign countries, are not employed by him, nor are they engaged in national pursuits. Consequently, there are powerful motives for not exempting persons of this description from the jurisdiction of the country in which they are found, and no one motive for requiring it. The implied license, therefore, under which they enter, can never be construed to grant such exemption.”
That view has been reaffirmed and applied by this Court on several occasions. United States v. Diekelman, 92 U. S. 520, 525, 526; Wildenhus’s Case, 120 U. S. 1, 11; Nishimura Ekiu v. United States, 142 U. S. 651, 659; Knott v. Botany Mills, 179 U. S. 69, 74; Patterson v. Bark Eudora, 190 U. S. 169, 176, 178; Strathearn S. S. Co. v. Dillon, 252 U. S. 348, 355-356. And see Buttfield v. Stranahan, 192 U. S. 470, 492-493; Oceanic Steam Navigation Co. v. Stranahan, 214 U. S. 320, 324; Brolan v. United States, 236 U. S. 216, 218. In the Patterson Case the Court added:
“ Indeed, the implied consent to permit them [foreign merchant ships] to enter our harbors may be withdrawn, and if this implied consent may be wholly withdrawn it may be extended upon such terms and conditions as the government sees fit to impose.”
In principle, therefore, it is settled that the Amendment could be made to cover both domestic and foreign [126]*126merchant ships when within the territorial waters of the United States. And we think it has been made to cover both when within those limits. It contains no exception of ships of either class and the terms in which it is couched indicate that none is intended. Such an exception would tend to embarrass its enforcement and to defeat the attainment of its obvious purpose, and therefore cannot reasonably be regarded as implied.
In itself the Amendment does not prescribe any penalties, forfeitures or mode of enforcement, but by its second section1 leaves these to legislative action.
With this understanding of the Amendment, we turn to the National Prohibition Act, c. 85, 41 Stat. 305, which was enacted to enforce it. The act is a long one and most of its provisions have no real bearing here. Its scope and pervading purpose are fairly reflected by the following excerpts from Title II:
“ Sec. 3. No person 2 shall on or after the date when the eighteenth amendment to the Constitution of the United States goes into effect, manufacture, sell, barter, transport, import, export, deliver, furnish or possess any intoxicating liquor except as authorized in this Act, and all provisions of this Act shall be liberally construed to the end that the use of intoxicating liquor as a beverage may be prevented.
“Sec. 21. Any room, house, building,, boat, vehicle, structure, or place where intoxicating liquor is manufactured, sold, kept, or bartered in violation of this title, and all intoxicating liquor and property kept and used [127]*127in maintaining the same, is hereby declared to be a common nuisance. . . .”
“ Sec. 23. That any person who shall,- with intent to effect a sale of liquor, by himself, his employee, servant, or agent, for himself or any. person, company or corporation, keep or carry around on his person, or in a vehicle, or other conveyance whatever, . . . any liquor ... in violation of this title is guilty of a nuisance . . .”
“ Sec. 26. When the commissioner, his assistants, inspectors, or any officer of the law shall discover any person in the act of transporting in violation of the law, intoxicating liquors in any wagon, buggy, automobile, water or air craft, or other vehicle, it shall be his duty to seize any and all intoxicating liquors found therein being transported contrary to law. . . .”
Other provisions show that various penalties and forfeitures are prescribed for violations of the act; and that the only instance in which the possession of intoxicating liquor for beverage purposes is recognized as lawful is where the liquor was obtained before the act went in effect and is kept in the owner’s dwelling for use therein by him, his family, and his bona fide guests.
As originally enacted the act did not in terms define its territorial field, but a supplemental provision3 after-wards enacted declares that it “ shall apply not only to the United States but to all territory subject to its jurisdiction,” which means that its field coincides with that of the Eighteenth Amendment. There is in the act no provision making it applicable to domestic merchant ships when outside the waters of the United States, nor any provision making it inapplicable to merchant ships, either domestic or foreign, when within those waters, save in the Panama Canal. There is a special provision dealing [128]*128with the Canal Zone 4 which excepts “ liquor in. transit through the Panama Canal or on the Panama Railroad.” The exception does not discriminate between domestic and foreign ships, but applies to all liquor in transit through the canal, whether on domestic or foreign ships. Apart from this exception, the provision relating to the Canal Zone is broad and drastic like the others.
Much has been said at the bar and in the briefs about the Canal Zone exception, and various deductions are sought to be drawn from it respecting the applicability of the act elsewhere. Of course the exception shows that Congress, for reasons appealing to its judgment, has refrained, from attaching any penalty or forfeiture to the transportation of liquor while “ in transit through the Panama Canal or on the Panama Railroad.” Beyond this it has no bearing here, save as it serves to show that where in other provisions no exception is made in respect of merchant ships, either domestic or foreign, within- the waters of the United States, none is intended.
Examining the act as a whole, we think it shows very plainly, first, that it is intended to be operative throughout the territorial limits of the United States, with the single exception stated in the Canal Zone provision; secondly, that it is not intended to apply to domestic vessels when outside the territorial waters of the United States, [129]*129and, thirdly, that it is intended to apply to all merchant vessels, whether foreign or domestic, when within those waters, save as the Panama Canal Zone exception provides otherwise.
In so saying we do not mean to imply that Congress is without power to regulate the conduct of domestic merchant ships when on the high seas, or to exert such control over them when in foreign waters as may be affirmatively or tacitly permitted by the territorial sovereign; for it long has been settled that Congress does have such power over them. Lord v. Steamship Co., 102 U. S. 541 ; The Abby Dodge, 223 U. S. 166, 176. But we do mean that the National Prohibition Act discloses that it is intended only to enforce the Eighteenth Amendment and limits its field of operation, like that of the Amendment, to the territorial limits of the United States.
The plaintiffs invite attention to data showing the antiquity of the practice of carrying intoxicating liquors for beverage purposes as part of a ship’s sea stores, the wide extent of the practice and its recognition in a congressional enactment, and argue therefrom that neither' the Amendment nor the act can have been intended to disturb that practice. But in this they fail to recognize that the avowed and obvious purpose of both the Amendment and the act was to put an end to prior practices respecting such liquors, even though the practices had the sanction of antiquity, generality and statutory recognition. Like data could be produced and like arguments advanced by many whose business, recognized as lawful theretofore, was shut down or curtailed by the change in national policy. In principle the plaintiffs’ situation is not different from that of the innkeeper whose accustomed privilege of selling liquor to his guests is taken away, or that of the. dining-car proprietor who is prevented from serving liquor to those who use the cars which he operates to and fro across our northern and southern boundaries.
[130]*130It should be added that after the adoption of the Amendment and the enactment of the National Prohibition Act Congress distinctly withdrew the prior statutory recognition of liquors as legitimate sea stores. The recognition was embodied in § 2775 of the Revised Statutes, which was among the provisions dealing with customs administration, and when, by the Act of September 21,1922, those provisions were revised, that section was expressly repealed along with other provisions recognizing liquors as legitimate cargo. C. 356, Title IV and § 642, 42 Stat. 858, 948, 989. Of course, as was observed by the District Court, the prior recognition, although representing the national policy at the time, was not in the nature of a promise for the future.
It therefore is of no importance that the liquors in the plaintiffs’ ships are carried only as sea stores. Being sea stores does not make them liquors any the less; nor does it change the incidents- of their use as beverages. But it is of importance that they are carried through the territorial waters of the United States and brought into its ports and harbors. This is prohibited transportation and importation in the sense of the Amendment and the act. The recent cases of Grogan v. Walker & Sons and Anchor Line v. Aldridge, 259 U. S. 80, are practically conclusive on the point. The question in one was whether carrying liquor intended as a beverage through the United States from Canada to Mexico was prohibited transportation under the Amendment and the act, the liquor being carried in bond by rail, and that in the other was whether the transshipment of such liquor from one British, ship to another in the harbor of New York was similarly prohibited, the liquor being in transit from Scotland to Bermuda. The cases were considered together and an affirmative answer was given in each, the Court saying in the opinion, p. 89:
“ The Eighteenth Amendment meant a great revolution in the policy of this country, and presumably and [131]*131obviously meant to upset a good many things on as well as off the statute book. It did not confine itself in any meticulous way to the use of intoxicants in this country. It forbade export for beverage purposes elsewhere. True this discouraged production here, but that was forbidden already, and the provision applied to liquors already lawfully made. See Hamilton v. Kentucky Distilleries & Warehouse Co., 251 U. S. 146, 151, n. 1. It is obvious that those whose wishes and opinions were embodied in the Amendment meant to stop the whole business. They did not want intoxicating liquor in the United States and reasonably may have thought that if they let it in some of it was likely to stay. When, therefore, the Amendment forbids not only importation into and exportation from the United States but transportation within it, the natural meaning of the words expresses an altogether probable intent. The Prohibition Act only fortifies in this respect the interpretation of the Amendment itself. The manufacture, possession, sale and transportation of spirits and wine for other than beverage purposes are provided for in the act, but there is no provision for transshipment or carriage across the country from without. When Congress was ready to permit such a transit for special reasons, in the Canal Zone, it permitted it in express words. Title III, § 20, 41 Stat. 322.”
Our conclusion is that in the first ten cases — those involving foreign ships — the decrees of dismissal were right and should be affirmed, and in the remaining two— those involving domestic ships — the decrees of dismissal were erroneous and should be reversed with directions to enter decrees refusing any relief as respects the operations of the ships within the territorial waters of the United States and awarding the relief sought as respects operations outside those waters.
Decrees in Nos. 659, 660, 661, 662, 666, 667, 668, 669, 670 and 678, Affirmed.
Decrees in Nos. 693 and 694, Reversed.
[132]*132Mr. Justice McReynolds, dissents.