Globally, terrorists have shown an increasing interest in
using small boats to attack military and commercial shipping
and maritime facilities. The tactics and techniques of using
commercial or non-commercial vessels (under 500 tons) or
swimmers to emplace or deliver improvised explosive devices have
proven effective and exportable. Contemporary operational practices
by transnational terrorist groups include refining proven attack
methods, sharing lessons learned, and encouraging others to adopt
effective tactics. Thus, the possibility of such attacks in
U.S. waters should not be ignored.
The small-boat threat needs to be addressed, but rather than
focusing on this particular terrorist tactic, Congress and the
Administration should invest in assets that improve the overall
security of the maritime domain. The maritime sector is a large and
diverse field with unique and daunting threats. Efforts should be
expanded to improve U.S. situational awareness and law enforcement
response rather than fixating on specific attack scenarios
involving small boats or other terrorist threats.
The Small-Boat Threat
The definition of "small-boat threat" encompasses a variety of
possible weapon-delivery vehicles, tactics, and payloads. Vessels
include everything from large craft such as small freighters, large
privately owned yachts, fishing trawlers, and commercial tugs to
dinghies, jet-skies, and submarines, including
mini-submarines like those used by the Japanese in the attack
on Pearl Harbor.
An attack could involve suicide bombers, as in the case of the
attack on the USS Cole, or vessels on autopilot or remotely
controlled. Improvised explosive devices could be delivered or
emplaced by boats or swimmers (assisted or unassisted by breathing
devices). This could involve placing a "parasite" on the hull of a
craft or deploying tethered (anchored to the sea bottom) or
untethered (floating) mines in a sea lane, waterway, or port
Besides conventional explosives, the bombers could detonate
nuclear, biological, chemical, or radiological devices. Attacks
could occur while the targeted ship is docked at shore, approaching
a port, sailing in international waters, or in U.S. or Canadian
coastal waterways. In addition to ships, attacks could target port
facilities; commercial infrastructure (e.g., an entertainment
pier, bridge piling, or pipeline); or public events.
How Small-Boat Attacks Are Carried
In many respects, small-boat threats resemble other terrorist
plots and have a similar signature. They require recruiting,
training and planning, surveillance and intelligence
collection, operational security, logistical support, rehearsals,
information operations, and execution.
On the other hand, these threats have some unique
characteristics and considerations. They can require unique
attributes and knowledge such as maritime skills (e.g., sailing and
scuba diving); familiarity with the target area (such as traffic
patterns near a port facility); or explosives training. Unique
environmental concerns that can affect the planning and conduct of
maritime attacks include weather, tides, and other variables that
could affect the dependability and reliability of the strike
method. For example, salt, water, and wind can adversely affect
weapons delivery and detonation.
Terrorists like predictability. They like to know the obstacles
that they will face and the probable results of an attack.
Uncertainties in the maritime domain could significantly affect the
desirability of employing the small-boat attack method. For
example, large public events like a "tall ship" week or a
national sporting event might seem inviting targets because of the
large crowds of people and the public attention focused on the
events. However, large, one-time events are less promising targets
because of the additional security and the greater difficulty in
predicting the security conditions.
Often, strikes on public venues are more appealing to "lone
wolf" attackers who might not weigh the risks and benefits of less
well-planned operations as carefully. Likewise, targets such
as liquefied natural gas (LNG) tankers or other ships carrying
hazardous materials might seem to present tempting
opportunities to generate spectacular catastrophic affects.
However, from material on the Internet, terrorists already know of
the debate over whether or not a small-boat attack could
realistically achieve a catastrophic outcome.
On the other hand, normal commercial traffic and port operations
bear many of the same characteristics of a desirable terrorist
target, including limited responsive security and highly
predictable patterns of behavior. For example, high-value ships
such as cruise ships and tankers carrying extremely hazardous
materials are much more vulnerable when entering or leaving
restricted navigable waters along the U.S. coastline, in port
areas, or along domestic waterways. During these periods, a large
ship typically has a pilot on board, is moving at a low speed, and
is following a tight and predictable course because of underwater
obstructions and maritime traffic.
Previous al-Qaeda Small-Boat
The most prominent small-boat attack on a military ship
occurred on October 12, 2000, when al-Qaeda operatives detonated a
small boat filled with explosives against the hull of the USS
Cole, which was refueling in the port of Aden, Yemen. The
attack killed 17 U.S. sailors and wounded 39 others. It also
garnered much publicity for al-Qaeda, which subsequently
highlighted the attack in its recruiting videos and other
In October 2002, al-Qaeda undertook its first successful attack
against a commercial ship using a small boat. Its operatives rammed
the French supertanker Limburg with a small fishing
craft packed with explosives. The attack, which occurred while the
Limburg was 12 miles off the coast of Yemen, killed one crew
member, injured 12 others, and caused a spill of 50,000 barrels of
crude oil along 45 miles of coastline.
Other terrorist groups besides al-Qaeda have attempted to use
small boats as weapons-delivery vehicles. On November 7, 2000, a
Hamas suicide bomber aboard a fishing boat tried to attack an
Israeli patrol craft sailing off the Gaza Strip. Alert crew members
detected the threat and sank the boat before the Hamas operative
could consummate the attack. The Tamil Tigers have also attempted a
number of improvised maritime attacks in Sri Lanka.
In addition to terrorist threats, transnational criminals have
used similar tactics to smuggle drugs, weapons, humans, and other
contraband. These include everything from building
mini-submarines to smuggle drugs across the Gulf of Mexico to
trafficking Cuban refugees to Key West. Many of the operational
practices employed by transnational criminals are adaptable to
terrorist attacks. (Conversely, countermeasures designed to
address small-boat threats might also be valuable in combating
illicit trafficking by small boats.)
How Serious Is the Threat?
The risks associated with small-boat threats are complex. An
assessment of risk combines an evaluation of criticality (or
consequences), threat, and vulnerability. Three major risks
connected with small-boat threats should be considered.
The Psychological Impact. Research data make a compelling
case that "man-made malicious" events create more fear,
apprehension, and uncertainty than natural disasters or accidents.
Almost every week, the U.S. experiences maritime incidents that are
equivalent to a small-scale terrorist attack in terms of
endangering life and property. These range from boating episodes
involving individuals to commercial industrial accidents that
put hundreds of lives and millions of dollars of infrastructure at
The United States has also experienced a number of large-scale
maritime disruptions, which have affected thousands to tens of
thousands of lives and hundreds of billions of dollars in damage.
These include everything from the Texas City (1947) and San
Francisco (1944) disasters, which involved large commercial ships
carrying extremely hazardous materials, to Hurricane Katrina,
which crippled the ports of New Orleans and Mobile. A terrorist
attack of similar scale would certainly have a significantly
greater impact on the public, particularly because many Americans
have only a minimal appreciation of what occurs in the maritime
domain. Anxiety is always greater when individuals are less
familiar with the situation.
The impact of a terrorist attack might be reflected in many
different behaviors and attitudes, from undermining the confidence
of Americans in their government to panic buying because of the
fear of economic disruption. The scale and duration of
psychological damage could vary significantly, depending on the
nature of the incident and the character of the response.
Physical Destruction.A small-boat attack is unlikely to
cause a large loss of life or property unless it involves a weapon
of mass destruction or highly hazardous material that causes a
large-scale fire or explosion. Even a large-scale disaster
involving thousands of lives and billions of dollars in damage
is unlikely to have long-term negative consequences for the
In many respects, the response required in the event of a
small-boat attack would resemble the response to a fire, explosion,
or industrial accident. Thus, many of the current safety measures,
equipment, drills, and training required for maritime safety
would be applicable to reducing the loss of life and property in
the event of a small-boat attack. Likewise, any measures to improve
overall safety, firefighting assets, all-hazards disaster response
capabilities, search and rescue, other emergency services, and
salvage and recovery would contribute to reducing damage in the
event of a successful attack.
Disruption of Services.Much of the U.S. maritime
infrastructure is clustered near urban centers. Thus, attacks might
disrupt mass transit, interrupt delivery of goods and services, or
require the evacuation of local populations. Some attacks
might seek to disable larger vessels to block waterways, bridges,
or tunnels. Physical disruptions would likely be highly localized
and have little impact on the overall economy or long-term economic
growth, even in the case of large-scale disasters.
Near-term economic impact might be more significant and
widespread if terrorists conducted multiple attacks at
multiple locations or if the attack affected the national supply
chain. Government (U.S., Canadian, or Mexican) and/or
private-sector responses after a strike (such as closing ports of
entry) might be more likely to have a significant economic impact
than would the direct results of the physical destruction caused by
the attack itself.
On the other hand, individual companies or industries might
suffer long-term negative affects, such as the cruise industry if a
cruise ship were attacked. This might be reflected in increased
insurance rates or loss of customer confidence.
The Scope of the Challenge
The small-boat problem is complicated by the magnitude of areas
and activities encompassing small-boat activity; the lack of
situational awareness by federal, state, and local authorities; and
the limited capacity to interdict active threats.
Policing a Vast Domain. Small boats operate on thousands
of miles of U.S. coastline, inland waterways, and lakes.
Frequent undeclared entries by small boats occur between the U.S.
and Canada and between the U.S. and the Bahamas every day. On any
given day, the number of small craft in U.S. waters is vast.
Thousands of boats are bought and sold every year, and many small
boats are operated with minimal training or licensing requirements.
In many areas, small boats operate in proximity to high-value ships
and maritime infrastructure without restriction.
Situational Awareness. The requirement for
situational awareness in U.S. ports, coastal areas, and
waterways evolved primarily in response to the need for aids to
navigation and safety. Situational awareness to support physical
security and law enforcement activities was not a primary
Post-9/11 situational awareness has been enhanced by
adapting existing technologies, such as surface radars in some
ports, and by applying new technologies, such as infrared video
surveillance and GPS. Few of these capabilities have been or can be
applied practically to the monitoring of small-boat activities,
although there are some ongoing initiatives. For example, the
Coast Guard Research and Development Center has experimented
with employing Navy sonobouys to detect small boats in high-density
smuggling areas, but implementing such solutions has major
technical and cost implications.
Interdiction and Response. Local, state, and federal law
enforcement have limited capability to detect threats, and standoff
detection is usually restricted to meters at best. For example, the
Department of Homeland Security, the Department of Defense, and
some local law enforcement authorities have the capability to scan
the hulls of boats for parasites. Current detection capabilities
are a mix of intrusive and non-intrusive systems. Almost of all of
them are time-consuming and costly, and almost all of them present
significant "false negatives" and "false positives" problems in
attempting to identify threats.
Law enforcement at all levels also has very limited
capacity to disable small craft or swimmers and ineffective
response times in meeting unanticipated threats. Methods of
incapacitation mostly involve the use of potentially lethal force.
Rules for the employment of lethal force are not consistent across
government agencies. In addition, methods for disabling small
boats using non-lethal technologies are neither widely available
nor particularly effective.
Only the U.S. Navy has any notable capacity to detect and clear
mines and improvised explosive devices at sea or in waterways. No
dedicated domestic assets can address waterborne mines. The U.S.
navy has conducted some research and has developed some capability
to detect and interdict swimmers, but this capacity is not widely
available for U.S. ports or waterways. Any application of
additional technologies or capabilities for interdiction and
response has significant cost and technical implications.
Ensuring Economic Competitiveness.Moving people, goods,
and services by sea and waterway is extremely cost-effective. In
addition, waterborne traffic, while not without environmental
consequences, produces much less air pollution than does
moving goods by truck. A significant expansion of domestic
maritime traffic for the transportation of goods and people
could give the United States a key economic competitive advantage
in the 21st century. Smaller craft could play a critical role in
this economic expansion. The key challenge to exploiting this
potential advantage will be public and private investment in
Currently, the nation as a whole does a poor job of investing in
maritime infrastructure. Federal and state laws do not provide
adequate incentives and in some cases discourage investment. In
regard to security, this provides a dual challenge to
policymakers. On the one hand, further excessive
regulation and restrictions in the name of enhancing security
will only further discourage investment. On the other hand, as the
nation increasingly exploits its ability to move by sea, maritime
infrastructure will become even more critical to the economy,
and concerns over its security will become even more pressing.
The U.S. Response
Post-9/11 security initiatives have only marginally
improved the U.S. capacity to deal with the small-boat threat. The
recently adopted International Maritime Organization
International Ship and Port Facility Security Code and the
corresponding requirements in the U.S. Maritime
Transportation Security Act address small-boat threats only
incidentally by requiring vulnerability assessments, security
plans, and security coordinators.
U.S. law requires ships over 500 tons to provide 96 hours notice
to the U.S. Coast Guard before entering U.S. waters. This
requirement does not address the small-boat threat.
Following the attack on the Cole, the U.S. Navy and many
of its foreign counterparts substantially improved their force
protection procedures. These better military defenses mean that
terrorists in the future will more likely choose to attack softer
targets such as commercial vessels flagged in the U.S. or friendly
Since 9/11, security has received increased emphasis in
U.S. ports and waterways, including more coordination among
federal, state, and local entities; greater access control; and
added security measures. Some security measures have been
introduced specifically to address the small-boat threat. For
example, LNG tankers are escorted into port and guarded,
although other more vulnerable and volatile hazardous cargo is
often not given the same attention. While in port, cruise ships are
required to post a picket craft to warn off or interdict small
Some ports have established operational coordination or
information sharing centers, such as Operation Seahawk in
Charleston, South Carolina. Typically, these centers do not focus
on the small-boat threat, although some coordinate reports of
suspicious activity or investigations that might uncover such a
While there have also been some efforts to increase and
coordinate police, county sheriff, state game and wildlife, and
U.S. Coast Guard waterborne patrolling, these programs are
modest. In some cases, volunteer groups such as state maritime
defense forces have been used to supplement waterborne
Development of the national maritime security strategy and the
Maritime Operations Threat Response Plan has improved maritime
security coordination overall, but it does not address the
small-boat threat specifically.
There have been some marginal efforts to coordinate
research and development of technologies and techniques and tactics
among the Navy, the U.S. Coast Guard, the National Laboratories,
federally funded research and development centers (such as RAND and
the Homeland Security Institute), and other federal and
private-sector entities. However, many disparate pilot projects,
experiments, and ongoing initiatives are poorly coordinated and
lack a clear plan to operationalize the research results.
In June 2007, the U.S. Coast Guard plans to convene a major
conference of maritime stakeholders to propose new measures for
dealing with the small-boat threat. The recommendations will likely
include a combination of new regulatory requirements and
sharing best practices.
Countermeasures generally fall into one of three categories, and
each set of solutions faces significant challenges.
Identification and Accreditation. These measures
include proposals for new regulatory regimes requiring additional
stipulations for licensing individual operators and craft;
national standardization of licensing processes and documents
(including both the licenses themselves and "breeder"
documents such as the documents used to verify identity and
legal status); reporting of lost and stolen licenses and craft; and
requirements for transponders, which would enable authorities
to identify and track small boats.
These proposals raise significant cost and effectiveness
issues that need to be addressed, as well as significant issues
concerning cost-sharing and responsibility among federal, state,
and local entities. Identification and accreditation regimes
will also raise privacy concerns similar to those involved in
implementing REAL ID. Further regulation of the maritime transport,
boating, and recreation industries could have negative
Another challenge is identifying and accrediting the many small
boats in U.S. waters that come from outside the United States,
particularly from Canada and the Bahamas and/or that are registered
overseas and licensed under flags of convenience. One set of
proposals would extend the 96-hour notification requirement to all
ships (even those under 500 tons) entering U.S. waters.
Yet proposals to extend notification requirements to small boats
raise a number of concerns. For example, many small boats can
travel to U.S. waters in less than 96 hours (e.g., from Canada,
Mexico, and the Bahamas). Small-boat owners are concerned about the
cost and inconvenience of complying with such regulations. In
addition, such reporting would generate mounds of data, and
screening and evaluating those data for useful information poses
significant cost and human capital challenges.
Finally, identification and accreditation programs are effective
when combined with capabilities to investigate fraud, identify and
respond to suspicious activities and persons, and prosecute
Improving Situational Awareness and Detecting
Threats. These measures could involve a range of activities
from "neighborhood watch" and public awareness programs to
technologies that provide wide-area surveillance and standoff
detection of explosives and materials used in weapons of mass
Identifying and monitoring small craft and swimmers poses
serious technological challenges. For example, distinguishing small
boats and swimmers from waves is often technologically
difficult. Detecting suspicious materials at a distance is
perhaps the most daunting technical challenge. The costs of
establishing and maintaining wide-area surveillance are
Finally, situational awareness and threat detection are
effective only if they are linked to responsive investigation
of suspicious activities and interdiction of threats.
Controlling Access and Interdicting Threats. This
approach involves restricting access to sensitive areas, which
might include critical infrastructure, extremely hazardous
material, national icons, high-value ships such as passenger ships
or ferries, or densely populated areas.
Interdiction raises issues concerning the manpower and
capabilities available to control access and conduct interdiction.
For example, significantly enhancing community policing at sea
could be extremely costly. In some cases, restricting or
controlling passage is impractical or would significantly
disrupt the movement of goods, people, and services.
The most significant technical challenge is developing
non-lethal disabling technologies to limit the requirement for
employing deadly force. Effective interoperable communications,
information sharing, and coordinating joint action among
federal, state, and local authorities and the private sector remain
Mitigating the Threat
The maritime domain has a vast number of vulnerabilities,
and terrorists have many options and opportunities for determining
how, when, and where to attack maritime infrastructure. Fixating on
a particular method of attack or trying to protect a
particular target set is a self-defeating strategy that not
only imposes significant costs on the defender, but also can easily
be circumvented by an adaptive enemy.
In that regard, focusing specifically on the small-boat threat
is probably not the best way to address the challenge. Rather,
maritime security solutions should focus on:
- Ensuring resiliency. Trade accounts for one-third of the
U.S. economy, and much of that trade and a significant portion of
the nation's transportation and energy infrastructure depends on or
is located near maritime infrastructure. The most important
national objective in the maritime domain should be to ensure that
commerce continues regardless of any natural or man-made
- Getting the biggest bang for the buck. Security
investments should be focused on initiatives that provide the most
value for improving maritime security overall. Hard choices need to
be made. Piecemeal investments in maritime security will add little
real security. On the other hand, effective counterterrorism
operations that focus broadly on identifying, investigating, and
thwarting terrorist activities and plots in the maritime domain
offer more value than those that focus narrowly on trying to deny
terrorists access to a specific target or delivery means.
What the Government Should Do
To create the most effective public policies to keep the nation
safe, free, and prosperous, Congress and the Administration must
take a broad and long-term view of the small-boat threat. Any
proposed efforts should:
- Address economic competitiveness, not just security, with
solutions that support both objectives. In particular, the
Administration should not impose significant new regulatory
restrictions on the operation and licensing of small boats and
small-boat operators. Such measures will add little security
at significant cost.
- Insist on programs that best enhance the overall
security of the maritime domain and contribute to the resiliency of
maritime commerce. First and foremost, the government should
ensure that maritime commerce is not adversely affected in the
event of an incident. The Administration should complete, exercise,
and refine the plan required by the national maritime security
strategy to address issues of business continuity and
reconstitution after major disruptions in maritime commerce.
- Invest more heavily in Coast Guard modernization,
particularly in programs that improve situational awareness, law
enforcement, and special operations capabilities. Specifically,
priority funding should be given to Coast Guard initiatives that
expand the capacity of the service's maritime security teams,
develop capabilities for effective non-lethal interdiction of
small boats, extend visibility of craft over the horizon by using
unmanned aerial vehicles and other technologies, field new
state-of-the-art patrol craft, and increase law enforcement
investigation and intelligence means.
- Ensure the right balance of roles, missions, and resources
and close cooperation between U.S. Navy and U.S. Coast Guard
maritime security missions. The U.S. Navy should focus on
providing intelligence support and mine-clearing expertise and
capabilities, as well as sharing research and development in
countering small-boat threats with the Coast Guard. The Coast Guard
should lead in developing a national maritime domain awareness
system, expand its capabilities to investigate and interdict
potential threats, and work with state and local governments and
the private sector to share information and intelligence
- Respect the principles of federalism and exploit the
inherent advantages of a free-enterprise approach to providing the
most creative, efficient, and effective solutions. Homeland
security grants should be minimal. Instead, the federal government
should facilitate the sharing of best practices and allow state and
local governments and the private sector the freedom to innovate
and adopt measures that are most appropriate for their needs and
that would best perform the due diligence necessary to ensure
business continuity and disaster recovery.
Government should also encourage and provide incentives for craft
under 500 tons to employ transponder locator and identification
technologies. These transponders perform a function
similar to what OnStar offers for automobiles. Adopting these
technologies would enhance public safety and increase situational
awareness, and use of these systems would better enable the Coast
Guard and other rescue services to find craft in need of
assistance. The widespread use of transponders would also assist in
monitoring maritime traffic.
The Way Ahead
For the United States to develop a comprehensive and
multilayered approach to homeland security, it must address
the small-boat threat. While the maritime sector is a large and
diverse field with unique and daunting threats, the U.S. should
develop plans to improve U.S. situational awareness rather than
defend against specific threat types. Investing in measures that
bolster the U.S. economy and provide the best return for the amount
spent are also good approaches for formulating a protection
plan against small boats.
In the end, guarding U.S. maritime craft and infrastructure will
not only protect the resilience of the U.S. economy and
international trade, but also protect a sector that serves as a
source of enjoyment and work for millions of American citizens.
James Jay Carafano,
Ph.D., is Assistant Director of the Kathryn and Shelby Cullom
Davis Institute for International Studies and Senior Research
Fellow for National Security and Homeland Security in the Douglas
and Sarah Allison Center for Foreign Policy Studies at The Heritage
Foundation. The author would like to thank Austin Knuppe for his
assistance in putting together this paper