KEARSE, Circuit Judge:
This is an appeal by defendants Theodore Scott Jube, Steven Jube, and Darlene Brennan,1 from judgments in the United States [416]*416District Court for the Southern District of New York, Milton Pollack, Judge, convicting them of possession of marijuana with intent to distribute it in violation of 21 U.S.C. §§ 812, 955a (1976), and of conspiracy to possess, import into the United States, and distribute marijuana in violation of 21 U.S.C. §§ 846, 955c, and 963 (1976). The judgments of conviction were entered following court-approved agreements between defendants and the government pursuant to which the defendants pleaded guilty to the possession and conspiracy charges, charges of attempting to import marijuana into the United States were dismissed, and the defendants preserved their rights to appeal the denial of certain suppression motions.2 On appeal, defendants contend that the warrantless entry onto a ship on the high seas by agents of the United States Coast Guard violated their rights under the Fourth Amendment to the Constitution, and that their motion to suppress certain seized items, including thirty tons of marijuana, should therefore have been granted. For the reasons below, we conclude that the entry was lawful and we therefore affirm the convictions.
BACKGROUND
The material facts, which have been stipulated by the parties, concern the sighting of a ship by the Coast Guard in the northern Atlantic Ocean approximately 50 miles east of Cape Cod and the boarding of that vessel by Coast Guard agents on the following day. Shortly before 10:00 a. m. on September 24, 1980, a Coast Guard airplane flying a routine patrol off the New England coast sighted a freighter drifting with its engine off and its bow pointed south-southeast. The plane circled over the ship for about fifteen minutes, and determined that “Panama” and the name “ROONDIEP” appeared on the stern of the freighter. While the aircraft was circling, the ship started its engines and began heading due south; the starting of the engines was visible from the Coast Guard plane.
The Coast Guard plane soon resumed in its original northeastern direction, but a number of factors caused the pilot and copilot to be suspicious of the ROONDIEP. In their training programs the officers had learned that a typical type of boat on which contraband drugs were carried was a coastal freighter 150-200 feet in length, flying a foreign flag. The pilot and co-pilot had two years’ and one and one-half years’ experience, respectively, in flying patrols out of Cape Cod. In their previous missions the officers had seen many freighters; generally the freighters had been under way and many had been laden with cargo visible from the air. In their experience a freighter did not drift “dead in the water” unless something was wrong. Because the ROON-DIEP was a 210-foot freighter of apparent foreign registry, drifting dead in the water, with no visible cargo, and had started its engines as the aircraft was circling it, the officers contacted the Coast Guard communications center in Boston and asked that the name “ROONDIEP” and the description of the freighter be checked with the El Paso Intelligence Center (“EPIC”). EPIC is a computerized information center of the United States Drug Enforcement Administration which regularly supplies law enforcement agencies with information about vessels suspected of engaging in smuggling. Within the hour,3 the station in Boston reported that EPIC’s reply was “positive” and [417]*417included information that the ROONDIEP had aliases, including the “ROERDOMP” and the “BITTERN,” that most recently the ROONDIEP had been sighted anchored off Aruba and had left Aruba without going into port, and that there was reason to suspect that the vessel might be used to smuggle marijuana into the United States. (Later that day, EPIC informed the Coast Guard that the ROONDIEP was not in fact the same ship as the ROERDOMP, alias the BITTERN, which was suspected of smuggling. None of the other information provided by EPIC was retracted.) After receiving the first EPIC message, the aircraft officers contacted Lieutenant Steven Spencer in the Coast Guard’s Atlantic Area Command (“Comlantarea”) and reported their sighting of the ROONDIEP and EPIC’s positive identification. The lieutenant, who had eight years’ Coast Guard experience, instructed the plane to relocate the ROONDIEP and maintain surveillance of it until a Coast Guard ship could arrive; he then directed the Coast Guard cutter TAMAROA to intercept the ROONDIEP. Spencer also made official inquiries of the five major United States ports within a day’s steaming distance from the ROON-DIEP’s location, and contacted the Canadian Maritime Command in Halifax; he was informed that none of those ports had seen or heard from the ROONDIEP.4
The actions of Lieutenant Spencer, as well as those of the cutter TAMAROA, were supervised by Comlantarea’s Operational Intelligence Officer, Commander D. R. Herlihy, who had been extensively involved in the investigation of drug smuggling. Herlihy knew that for several years drug smugglers had used a technique known as the “mother ship” technique, in which a ship loaded with large quantities of marijuana hovers off the United States coast while smaller boats come to the ship, get the marijuana, and take it into shore. Herlihy knew that the “mother ships” often flew foreign flags and that a number of such ships seized by the Coast Guard over the years had flown the Panamanian flag.
At approximately 2:20 p. m., the TAMA-ROA, captained by Commander Anthony Pettit and having been advised of the ROONDIEP’s location by the aircraft pilots, approached the ROONDIEP, and established ship-to-ship radio communication. Conversation between the two ships ensued intermittently for 30 to 40 minutes. During the course of these conversations, the ROONDIEP informed the TAMAROA that its last port of call was Martinique; that its next port of call was as yet unknown because its original orders to go to “Maine or Canada” to pick up lumber had been can-celled; and that it was awaiting new orders, perhaps to go to Europe. The officers asked for permission to board the ROON-DIEP; the master of the ROONDIEP refused, saying that he was leaving United States waters and that he saw no need for the Coast Guard to board. Later the ROONDIEP master said he felt the weather was not conducive to bringing the TA-MAROA and the ROONDIEP together. When the TAMAROA advised the ROON-DIEP that the latter was headed toward a shallow area not part of the standard ship lanes for international traffic, the ROON-DIEP master replied that he was not concerned because the ship was in light condition and did not draw much water. On the basis of the circumstances and in particular the ROONDIEP’s responses over the radio, Pettit, a fifteen-year veteran of Coast Guard service, suspected that the ROON-DIEP might be involved in smuggling. Pettit relayed his information to Herlihy.
All of the circumstances, including the ROONDIEP’s appearance, location, actions, and radioed statements to the TAMAROA, led Herlihy to conclude that the ROON-DIEP appeared to be a “mother ship” carrying drugs that it wanted to smuggle into the United States. At Herlihy’s suggestion, appropriate government officials contacted Panamanian officials to obtain confirmation that the ROONDIEP was of Panamanian registry, to report the suspicion that it was carrying drugs, and to request permission to board it. Panamani[418]*418an officials, as they had done in past instances, gave permission for the Coast Guard to board and search the ship, acting as agent for the Government of Panama. At approximately 8:00 p. m., Herlihy relayed word of the Panamanian government’s permission to the TAMAROA, whose commander determined, in the interests of safety, to put off until morning any attempt to board the ROONDIEP. Throughout September 24 the TAMAROA kept pace with the ROONDIEP which, as the day and evening wore on, altered its course from 180° (due south), to 150°, to 120°, to 112°, to 100°, to 90° (due east), and finally, just after midnight, to 95°.
By the morning of September 25 the ROONDIEP was approximately 200 miles from the coast of the United States. At 6:10 a. m. the TAMAROA called the ROON-DIEP on bridge-to-bridge radio. During the twenty-minute conversation that ensued the TAMAROA twice ordered the ROONDIEP to “heave to”; the ROON-DIEP responded that it was in international waters, that it did not wish to be boarded, and that it did not recognize the Coast Guard’s right to board it. Finally, the ROONDIEP asked whether the TAMAROA intended to use force and the latter responded in the affirmative, stating that it was authorized to do so by the Panamanian government. At 6:30 a. m., when the ROONDIEP still refused to stop, the TA-MAROA fired six bullets from a .50 caliber machine gun into the water in front of the ROONDIEP’s bow. At 6:34 a. m., under protest, the ROONDIEP stopped and put a ladder over its side. At 6:38 a. m., six Coast Guard agents, led by Ensign John An-drezjewski, boarded the ROONDIEP. After asking to see the ship’s registry papers, Andrezjewski asked the ROONDIEP’s captain, Colin Gregory, what cargo the ship was carrying and was told that it carried none. At 6:58 a. m. Andrezjewski went to the cargo hold, where he smelled marijuana and saw hundreds of bales of marijuana. When he returned to Gregory and asked what was in the hold, Gregory responded that Andrezjewski knew what was in the hold. Andrezjewski thereupon arrested Gregory and the six other persons found aboard the ROONDIEP, who included the defendants here. Following the arrests, the Jube brothers told the Coast Guard officers that they had obtained the marijuana in Colombia some weeks earlier and had come north to deliver it, a task for which each crew member was to receive $100,000.
After being indicted for the narcotics offenses described above, the defendants moved unsuccessfully for the suppression of various items of evidence against them, including items seized from the ROONDIEP and all post-arrest statements made by them aboard the ROONDIEP. On the basis of the stipulated facts the district court ruled, in an opinion reported at 507 F.Supp. 480, that the boarding was authorized by 14 U.S.C. § 89(a) (1976)5 and by the consent of the Panamanian government, and that the Coast Guard’s reasonable suspicions of criminal activity made the boarding of the ROONDIEP a constitutionally permissible investigatory stop under the authority of [419]*419Terry v. Ohio, 392 U.S. 1, 88 S.Ct. 1868, 20 L.Ed.2d 889 (1968). In addition, relying on United States v. Matlock, 415 U.S. 164, 171, 94 S.Ct. 988, 993, 39 L.Ed.2d 242 (1974), the court held that the Fourth Amendment was satisfied by the acquisition of Panama’s consent to the boarding since Panama had authority over the vessel. *
Following the court’s denial of the suppression motions the defendants agreed to plead guilty to the charges of possession and conspiracy to possess, import, and distribute marijuana, in exchange for the dismissal of the remaining count, which charged them with attempting to import marijuana. The agreement allows them to pursue on appeal their challenge to the Coast Guard’s stop and boarding of the ROONDIEP on the ground that those actions violated the defendants’ rights under the Fourth Amendment.
DISCUSSION
The issues for our consideration on this appeal are narrowly circumscribed by reason of the limited scope of the parties’ contentions. The defendants attack only the stopping and boarding of the ROON-DIEP; they do not challenge the Coast Guard’s search that followed the boarding.6 Nor do the defendants contend that the Coast Guard lacked the requisite statutory or other governmental authorization for the boarding.7 For its part, the government concedes that the information possessed by the Coast Guard did not rise to the level of probable cause to seize the ship or those on board. The question presented thus is whether, in the absence of probable cause, the stopping and boarding of the ROON-DIEP was constitutionally permissible. We conclude that in the circumstances shown here, the stopping and boarding constituted a legitimate investigatory stop that was reasonable within the meaning of the Fourth Amendment.8
It is fundamental that governmental searches and seizures without war[420]*420rant or probable cause are per se unreasonable under the Fourth Amendment unless they fall within one of the Amendment’s few established and well-delineated exceptions. Schneckloth v. Bustamonte, 412 U.S. 218, 219, 93 S.Ct. 2041, 2043, 36 L.Ed.2d 854 (1973); Katz v. United States, 389 U.S. 347, 357, 88 S.Ct. 507, 514,19 L.Ed.2d 576 (1967). One such exception is the “stop and frisk” exception announced by the Supreme Court in Terry v. Ohio, supra, 392 U.S. 1, 88 S.Ct. 1868, 20 L.Ed.2d 889. In Terry, the Court ruled that even in the absence of probable cause law enforcement officers may briefly stop a person on the street for investigative purposes; if, however, the stop has the ef■fect of restraining the individual’s freedom to walk away, even though he has not been arrested, the person has been “seized” within the meaning of the Fourth Amendment, and that Amendment requires that the stop be reasonable.9 A determination of the reasonableness of the stop requires the analysis and balancing of two principal factors: the governmental need for the stop, and the degree of intrusiveness of the stop.
The first factor is itself composed chiefly of two elements. First is the nature and extent of the governmental interests involved. Law enforcement is, of course, a cognizable interest:
[421]*421One general interest is of course that of effective crime prevention and detection; it is this interest which underlies the recognition that a police officer may in appropriate circumstances and in an appropriate manner approach a person for purposes of investigating possibly criminal behavior even though there is no probable cause to make an arrest.
Terry v. Ohio, supra, 392 U.S. at 22, 88 S.Ct. at 1880. The second element of the government’s need to make the stop is the factual basis that implicates the governmental interests in question. Thus, as developed in Terry and in subsequent eases involving both pedestrians and persons in vehicles, the government is justified in pursuing its interest in preventing or detecting crime only if the officers are “aware of specific articulable facts, together with rational inferences from those facts that reasonably warrant suspicion” that the individual is, was, or is about to be engaged in criminal activity. E. g., United States v. Brignoni-Ponce, 422 U.S. 873, 884, 95 S.Ct. 2574, 2581-2582, 45 L.Ed.2d 607 (1975); United States v. Cortez, 449 U.S. 411, 101 S.Ct. 690, 66 L.Ed.2d 621 (1981). This standard is less stringent than probable cause, but it too is “an objective standard,” Terry v. Ohio, supra, 392 U.S. at 21, 88 S.Ct. at 1879-1880, requiring a “reasonable and articulable suspicion,” Reid v. Georgia, 448 U.S. 438, 100 S.Ct. 2752, 65 L.Ed.2d 890 (1980) (per curiam), and it means that legitimate investigatory stops cannot be made completely at random, Delaware v. Prouse, 440 U.S. 648, 654, 99 S.Ct. 1391, 1396, 59 L.Ed.2d 660 (1979), or at the “unfettered discretion of officers in the field.” Brown v. Texas, supra, 443 U.S. 47, 51, 99 S.Ct. 2637, 2640, 61 L.Ed.2d 357 (1979). In determining whether an officer’s suspicion was reasonable the “totality of the circumstances” must be considered, United States v. Cortez, supra, 101 S.Ct. at 695, and “due weight must be given, not to his inchoate and unparticularized suspicion or ‘hunch,’ but to the specific reasonable inferences which he is entitled to draw from the facts in light of his experience.” Terry v. Ohio, supra, 392 U.S. at 27, 88 S.Ct. at 1883. In sum, given appropriate articulable grounds for suspicion, an investigatory stop to prevent or interrupt a crime may be made in the absence of probable cause:
“The Fourth Amendment does not require a policeman who lacks the precise level of information necessary for probable cause to arrest to simply shrug his shoulders and allow a crime to occur or a criminal to escape.”
Adams v. Williams, 407 U.S. 143, 145, 92 S.Ct. 1921, 1923, 32 L.Ed.2d 612 (1972).
The remaining factor in evaluating the reasonableness of an investigatory stop is the degree of restraint imposed on the individual’s freedom. In general, if there is an official seizure of the person, even though there has not been a formal arrest, such a seizure is too intrusive to be supportable on less than probable cause. Dunaway v. New York, 442 U.S. 200, 99 S.Ct. 2248, 60 L.Ed.2d 824 (1979). In Dunaway, the restraint was the police officers’ taking the suspect from his neighbor’s home to the police station and detaining him there for questioning; he was not technically under arrest, but neither was he free to leave. On the other hand the Court has held that the interception of a moving vehicle, causing it to stop for questioning, is not so intrusive that probable cause is required. United States v. Brignoni-Ponce, supra; United States v. Cortez, supra 101 S.Ct. at 697; nor is it unduly intrusive to order that a person stopped for a traffic violation get out of his car. Pennsylvania v. Mimms, 434 U.S. 106, 98 S.Ct. 330, 54 L.Ed.2d 331 (1977). The courts of appeals, applying these principles, have held that stops at gunpoint generally amount to arrests and thus cannot be sustained in the absence of probable cause, see, e. g., United States v. Ceballos, 654 F.2d 177 (2d Cir. 1981); United States ex rel. Walls v. Mancusi, 406 F.2d 505, 508-09 (2d Cir.), cert. denied, 395 U.S. 958, 89 S.Ct. 2099, 23 L.Ed.2d 745 (1969); United States v. Beck, 598 F.2d 497 (9th Cir. 1979); United States v. Ramos-Zaragosa, 516 F.2d 141 (9th Cir. 1975), but that the “utilization of force in making a stop will not convert the stop into an arrest if it is precipitated by the conduct [422]*422of the individual being detained.” United States v. Beck, supra, 598 F.2d at 501; United States v. Vasquez, 638 F.2d 507, 523 (2d Cir. 1980).
In general, if there is reasonable ground for suspicion that will justify an investigatory stop, reasonable force may be used to effect that stop. In Michigan v. Summers, 452 U.S. 692, 101 S.Ct. 2587, 69 L.Ed.2d 340 (1981), the Supreme Court observed that
[i]n upholding the “frisk” employed by the officer in [Terry v. Ohio, supra], the Court assumed, without explicitly stating, that the Fourth Amendment does not prohibit forcible stops when the officer has a reasonable suspicion that a crime has been or is being committed. See id. [392 U.S.] at 32-33 [88 S.Ct. at 1885-1886] (HARLAN, J., concurring [“the officer . . . must first have constitutional grounds to insist on an encounter, to make a forcible stop.” (emphasis in original)]). Id., at 34 [88 S.Ct. at 1886] (WHITE, J., concurring [“the person may be briefly detained against his will while pertinent questions are directed to him.”]).
Id. at 2591 n.7. The Summers Court went on to state that in Adams v. Williams, supra,
the Court relied on Terry to hold that an officer could forcibly stop a suspect to investigate an informant’s tip that the suspect was armed and carrying narcotics.
101 S.Ct. at 2592 (footnote omitted).
Further, the intrusiveness of an investigatory stop does not become unreasonable merely by the fact that it lasts longer than a few minutes. In Summers, the Court upheld the detention of a person whose house was to be searched pursuant to a warrant that had been issued. As officers arrived to execute the warrant they encountered the respondent coming down his front steps; they took him back inside and detained him while they searched the premises. Although the duration of the detention is not clear from the Court’s opinion, it is apparent that a thorough search was conducted, since narcotics were found under a bar in the basement. In upholding the detention of the respondent while this search was going on the Court stated that
the exception for limited intrusions that may be justified by special law enforcement interests is not confined to the momentary, on-the-street detention accompanied by a frisk for weapons involved in Terry and Adams.12
Id. at 2593.
In sum, an officer having a reasonable suspicion, based on articulable, objective facts, that criminal activity is afoot may make an investigatory stop that is reasonable in both its duration and its intrusiveness into the individual’s legitimate privacy expectations. In balancing the government’s law enforcement interests against the individual’s interests it is generally true that the more intrusive the stop, the stronger the justification need be, see Michigan v. Summers, 452 U.S. 692, 101 S.Ct. 2587, 69 L.Ed.2d 340 (1981); United States v. Vasquez, supra, 638 F.2d at 520, and that “if probable cause is lacking, the intrusion must be no greater than the circumstance require,” id.
We believe these principles are as applicable to searches and seizures on the high seas as they are to searches and seizures on land. Assuming, as we do, the truth of the fundamental proposition that the Fourth Amendment itself applies to searches and seizures by government agents at sea, see note 8, supra, we see no reason to suppose that that portion of Fourth Amendment jurisprudence that governs the validity of investigatory stops, developed in land-based cases, is not also applicable at sea. There can be no question that there is a governmental interest to be served. The interest in preventing smuggling of contraband into the United States, or in detecting the commission of other acts in violation of [423]*423United States laws does not end at the twelve-mile limit. This law enforcement interest is reflected in several federal laws, not the least of which is 14 U.S.C. § 89(a), which provided the statutory authority for the Coast Guard boarding in the present case. See note 7, supra. Section 89(a), the full text of which is set out in note 5, supra, gives the Coast Guard the power to “make inquiries, examinations, inspections, searches, seizures, and arrests upon the high seas and waters over which the United States has jurisdiction, for the prevention, detection, and suppression of violations of laws of the United States,” and to use all necessary force to compel compliance with those laws.
Given these law enforcement interests, we cannot say as a general mattér either that the nature of the need to stop a vessel to obtain answers to relevant questions is significantly different from the need to make such stops of pedestrians or land vehicles, or that the intensity of that need is significantly less at sea than on land. The intensity of the need may well vary from land to sea, as in some instances the ability of the officials to continue surveillance of a suspect will be greater on land and in others it will be greater at sea. The factors that may affect the need, such as the openness of the medium traveled, or the weather, or the maneuverability of the vehicle, are factors to be weighed in evaluating the need to make an intrusion into the suspect’s interests, rather than reasons not to apply Fourth Amendment principles.
Finally, we find no basis for denying the government the use of investigatory stops at sea in the fact that many vessels include living quarters for their owners or their crew. While one has a more legitimate expectation of privacy in one’s living quarters than in other areas, this expectation has greater relevance to the scope of a search than to the intrusiveness of a stop. Further, there is no uniformity of circumstance such as to warrant a prohibition against “Terry stops” on the water: many boats have no residential quarters; conversely, some land vehicles do have such quarters. And some areas of the common automobile are entitled to greater privacy protection than others. E. g., Compare New York v. Belton, 453 U.S. 454, 101 S.Ct. 2860, 69 L.Ed.2d 768 (1981), with Robbins v. California, 453 U.S. 420, 101 S.Ct. 2841, 69 L.Ed.2d 744 (1981). Again, the differing expectations of privacy in various kinds of vehicles or vessels may result in differences in the balancing of the interests relevant in assessing the reasonableness of an investigatory stop, but they do not make inapplicable the principles that require the balancing to be done.
In short, we are aware of no compelling reason to fashion a different set of principles for treatment of searches and seizures on the high seas than have been developed by Terry and its progeny. See United States v. Williams, 617 F.2d 1063, 1095-99 (5th Cir. 1980) (en banc) (Rubin, J., concurring in result). See also United States v. Lee, 274 U.S. 559, 47 S.Ct. 746, 71 L.Ed. 1202 (1927), applying Fourth Amendment principles developed in the open fields of Hester v. United States, 265 U.S. 57, 44 S.Ct. 445, 68 L.Ed. 898 (1924), to the high seas. We conclude that any land-sea difference in governmental need or in intrusiveness affects only how the principles are applied, not their applicability.
Applying “Terry stop” principles to the case before us, we have no doubt that the Coast Guard’s stop and boarding of the ROONDIEP constituted a seizure of the ship and those on board within the meaning of the Fourth Amendment. The order that the ROONDIEP stop, enforced by the firing of shots in the water in front of its bow, clearly restrained its freedom of movement, and with it the freedom of those on board. Michigan v. Summers, supra; Terry v. Ohio, supra. We conclude, however, that, even excluding that bit of EPIC information that was erroneous and therefore retracted before the decision to board was made, the officials had reasonable, articulable grounds for suspecting the ROONDIEP of engaging in activities in violation of the laws of the United States, and that the stop and boarding were not unreasonably intrusive.
[424]*424The decision to stop and board the ROONDIEP was made on the basis of the observations and analyses of officials experienced in the prevention and detection of smuggling into the United States. They had previously dealt with many “mother ship” operations, in which a large vessel lingers offshore while other smaller boats come to pick up narcotics. When last sighted the ROONDIEP had hovered off the coast of Aruba for a time, leaving without going into port. When the Coast Guard first encountered the ROONDIEP it was hovering 50 miles off the United States coast, lying dead in the water for no apparent reason and with no visible cargo. When discovered by the Coast Guard airplane, the ROONDIEP immediately started its engines and commenced to move on. When asked its destination it stated that its original orders had been to go to “Maine or Canada” — an unusual lack of certainty. Nor had officials at the nearest major ports, which included two in Maine and one in Canada, ever heard from the ROONDIEP. The ROONDIEP also had no new orders for a new destination — a circumstance the experienced officers also found suspicious. Having given these suspicious answers, the ROONDIEP bit by bit altered its course until it ultimately was heading nearly directly out to sea. By morning it had moved to a point 200 miles off the coast. On the basis of all the circumstances, the officials were entitled to suspect, drawing on their experience, that the ROONDIEP was engaged in smuggling. The suspicion was reasonable and it justified further investigation.
The stop and boarding of the ROONDIEP were not an unreasonably intrusive means of investigating further. The Coast Guard’s suspicions justified a more extensive investigation than could be made merely through additional radio inquiries. The officers were not required to receive answers to their questions from whomever the ROONDIEP master chose to put on the radio. Nor were they required to continue to assess the veracity of the ROONDIEP’s answers through the inferior medium of airwaves rather than face-to-face questioning. Once the Coast Guard reasonably believed that it was receiving evasive answers from the ROONDIEP’s captain, it was reasonable to seek an interrogation in person. Given the ROONDIEP’s apparent attempt to escape, as well as the various factors indicating that the ROONDIEP might be involved in smuggling, the most practical means of investigation was to board the ROONDIEP.
The firing of warning shots to stop the ROONDIEP was not unreasonable, since reasonable force may be used if needed. The ROONDIEP had for some twenty minutes refused to stop upon request. The Coast Guard’s firing of shots into the water in front of the ship appears to have been the least drastic way to force the ship to stop, and the shots were directly attributable to the ROONDIEP’s refusal to submit to an authorized request to stop.
A law enforcement officer who has duly announced his authority and who has attempted to stop and question a suspect is not required “to simply shrug his shoulders,” . . . and abandon his investigation .... [T]he officer has the right to detain the suspect against his will. . . . Indeed, the officer “is entitled to make a forcible stop.”
United States v. Gomez, 633 F.2d 999, 1006 (2d Cir. 1980), cert. denied, 450 U.S. 944, 101 S.Ct. 1695, 68 L.Ed.2d 194 (1981) (quoting Adams v. Williams, supra, 407 U.S. at 145, 92 S.Ct. at 1922-1923). Since the firing of warning shots appears to have been no more intrusive than the circumstances required to get the ROONDIEP to stop, this action was not unreasonable. Nor does it appear that any force was used thereafter. Although it is to be presumed that the six-man boarding party was armed, there is no suggestion that they boarded the ROON-DIEP with guns drawn, or even displayed their guns to those on the ROONDIEP.10 [425]*425Cf. United States v. Arra, 630 F.2d 836, 838-39 (1st Cir. 1980) (“One of the three boarders, Seaman Arce, carried a loaded shotgun, and the other two had handguns. Seaman Arce stood guard over the crew . . . during the course of the document and safety inspection.”). And the parties’ stipulation indicates that it was only after the marijuana was found in the cargo hold that the Coast Guard officers placed the ROON-DIEP master and the other six persons found aboard under arrest.
Finally, the stop cannot be impeached on the basis of its duration. Defendants argue that the length of their investigatory detention was unreasonable because 48 minutes elapsed between the first order to stop and the eventual arrests. This contention has no merit in fact or law. First, the initial twenty minutes consisted not of a detention, but of the Coast Guard’s futile verbal attempts to persuade the ROONDIEP to stop. Further, the time required to stop and to board a 210-foot freighter cannot be equated with the time required to stop and to approach an automobile. Apparently four minutes elapsed between the warning shots and the ROON-DIEP’s stopping, and an additional four minutes were required for the boarding party to reach the ROONDIEP. These times seem expeditious in the circumstances. Nor can we say that the twenty minutes between the boarding at 6:38 a. m. and the discovery of the marijuana and arrests at 6:58 a. m. was an undue period. The record is silent as to what occurred during that interval; but we note that defendants’ brief on appeal states that after boarding and asking for the ship’s registry papers the Coast Guard “wasted no time” in descending to the cargo hold. In all, it appears that the detention during the investigatory stop was of reasonable duration.
CONCLUSION
The stop and boarding of the ROONDIEP were reasonable under the Fourth Amendment. Defendants’ motion to suppress was properly denied and their convictions are affirmed.