Honolulu Harbor and the Single-Port State: What Hawaiʻi’s Supply Chain Teaches Every Island

Why Hawaiʻi is a single-port state

Hawaiʻi’s Emergency Management Agency puts the problem in one sentence: as the only island state in America, Hawaiʻi relies on shipping for most of its food and supplies, so residents are asked to keep two weeks of emergency supplies in case a hurricane or tsunami damages ports and supply chains (HI-EMA). The State’s harbor planners reach the same conclusion from the cargo side. HDOT describes ocean cargo transport as the only viable means to serve every part of the local economy, from tourism and construction to national defense and agriculture (Honolulu Harbor 2050 Master Plan).

The figures below are all from HDOT’s own documents. Together they describe what ISPI calls supply chain singularity: a community whose daily needs pass through a single node with no practical land or air alternative at scale. The same pattern appears on islands across the Pacific, Caribbean and Indian Ocean, which is why ISPI tracks it in its ports and maritime security research hub.

How the hub-and-spoke system works

HDOT runs the State’s commercial harbors as one system. It operates on the M-H1 Daniel K. Akaka Marine Highway as a hub-and-spoke network, with Honolulu Harbor on Oʻahu as the hub. Cargo from the mainland and abroad arrives in Honolulu and is then distributed to five other islands served by seven commercial harbor facilities (HDOT Harbors Title VI plan, 2024). The master plan notes that cargo bound for the Neighbor Islands is transshipped from Honolulu on interisland barges, which links the harbor to the whole State’s economy (Honolulu Harbor 2050 Master Plan).

Oʻahu has a second commercial port. Kalaeloa Barbers Point Harbor, about 25 miles northwest of Honolulu, is the primary harbor for liquid-bulk and dry-bulk cargo and the hub for Hawaiʻi’s fuel and liquid asphalt supply. Crude oil does not use either harbor; it enters through an offshore mooring (Honolulu Harbor 2050 Master Plan). Jet fuel imports have their own node: the master plan identifies Pier 51A in Honolulu Harbor as the State’s main terminal for jet fuel imports, with a second manifold planned at Pier 43 (Honolulu Harbor 2050 Master Plan).

The Neighbor Islands have their own single points. In announcing a $40,146,750 federal Port Infrastructure Development Program grant on Oct. 27, 2026, HDOT described the Port of Kahului as Maui’s sole commercial port. The $56.1 million cargo yard expansion responds to the influx of construction materials, heavy equipment and modular housing that followed the August 2023 Lahaina wildfires, with completion targeted for 2029 (HDOT, Oct. 27, 2026).

The single points of failure inside the single port

The State’s plan is unusually candid about where Honolulu Harbor could fail. Four points stand out (Honolulu Harbor 2050 Master Plan):

• One usable entrance. The Main Entrance Channel is 4,000 feet long, 500 feet wide and 45 feet deep, and it is the only access to the harbor for ship transit.
• A closed second entrance. From 1963 to 1984 a bascule bridge let cargo ships use Kalihi Channel. In the mid-1980s the bridge was fixed in place and a second fixed bridge was added for truck traffic to Sand Island. Today only small vessels with drafts under 20 feet and air drafts under 13 feet can use that route.
• A bridge to the main container yard. In a modeled Great Aleutian tsunami, inundation restricted access to containers on Sand Island by affecting transit across the Sand Island Bridge.
• Debris in the channel. The same modeling showed storm surge could sink containers and contaminants to the harbor bottom, creating a navigation hazard for the relief vessels the islands would need most.

The plan’s response is to design for recovery. It designates Piers 1 and 2, at the harbor entrance, as the priority resiliency pier because relief vessels there face a lower risk of being blocked by sunken debris, and it recommends heavy-lift pads and hardened utility conduit to support emergency relief. It also recommends a feasibility study with the U.S. Army Corps of Engineers on reopening a second harbor entrance at Kalihi Channel (Honolulu Harbor 2050 Master Plan). The Corps’ Honolulu District describes the same issue in federal terms: the harbor’s single point of entry and exit for vessels creates time delays, inefficiencies and a single point of failure if there is an incident in the channel. Its Honolulu Deep-Draft Harbor Modification feasibility study began with a cost-sharing agreement with HDOT on Sept. 23, 2022, split evenly between federal and state funds (U.S. Army Corps of Engineers).

What Hurricane Lowell showed in September 2026

Hurricane Lowell tested the system in early September 2026. HDOT’s updates, summarized in the table, show both the speed of the federal and state reopening process and how exposed a small island is when its only harbor is damaged.

Hurricane Lowell and Hawaiʻi’s ports, September–October 2026

Date (2026)	What HDOT reported	Source
Sept. 8	Coast Guard Captain of the Port reopened Nāwiliwili and Kalaeloa Barbers Point harbors before 5 p.m.; Honolulu Harbor, Kaumālapaʻu (Lānaʻi) and Port Allen (Kauaʻi) stayed closed; options to open part of Honolulu Harbor to vessels over 200 gross tons under study	HDOT, Sept. 8, 2026
Sept. 9	Honolulu Harbor reopened by the Captain of the Port at 9:30 a.m.; it had been closed because of broken buoys at the harbor entrance. Kaumālapaʻu repairs began, with an estimate of two weeks	HDOT, Sept. 9, 2026
Sept. 10	Side-scan sonar used to find underwater hazards at Kaumālapaʻu; divers to direct cranes removing containers and debris; target to reopen Sept. 13	HDOT, Sept. 10, 2026
Sept. 13	Limited operations at Kaumālapaʻu for a special interisland barge carrying goods and fuel; only essential harbor personnel allowed, with Maui Police assisting access control	HDOT, Sept. 12, 2026
Sept. 27 to Oct. 2	Kaumālapaʻu reopened after inspection for daylight operations only; back to normal status as of Oct. 2	HDOT status board

Two points matter for planners. First, Honolulu Harbor did not need major structural damage to close: HDOT reported that the closure was due to broken buoys at the harbor entrance, and the reopening decision belonged to the Coast Guard Captain of the Port (HDOT, Sept. 9, 2026). Second, Lānaʻi’s recovery depended on clearing the waterway as much as fixing the pier. HDOT listed a sinkhole, the pier apron and containers and debris in the water as the work needed before vessels could return, and said it was working with community partners on alternatives for delivering consumer goods in the meantime (HDOT, Sept. 9, 2026).

Lowell followed Hurricane Lala, which ISPI examined in its review of the Hurricane Lala grid outage. Taken together, the two storms disrupted power, harbors and roads, which is why ISPI argues that island recovery planning should treat them as one system.

Hazards already on the planning record

HDOT’s master plan sets out the natural hazards the harbor must plan for (Honolulu Harbor 2050 Master Plan):

• Tsunami. Honolulu Harbor lies within the Tsunami Evacuation Zone. In the Great Aleutian tsunami simulation, all of the harbor’s piers were inundated with flow depths of 3 to 10 feet, enough to displace shipping containers and damage gantry cranes and equipment.
• Hurricane surge. Army Corps hurricane simulations cited in the plan predict a worst-case storm surge of 7 to 8 feet, with waves of 10 feet at the harbor entrance and over 35 feet just outside it.
• Sea level rise. Following the State’s 2017 Sea Level Rise Vulnerability and Adaptation Report, the plan uses a projection of 3.2 feet of sea level rise by 2060 for critical infrastructure and recommends raising piers and yards to match.
• Evacuation of vessels. HDOT and the Coast Guard require ships to leave the harbor before a hurricane or tsunami arrives when they can safely get underway; the Captain of the Port notifies vessel owners, operators and agents.

These hazards connect to ISPI’s tsunami preparedness guide and to the continuity planning steps in our continuity of operations guide for island local government, which applies the same thinking to county and state agencies.

Who secures the port, and where insider risk sits

Port security in Honolulu is layered. HDOT oversees security within harbor boundaries under plans approved by the Coast Guard, covering the Facility Security Officer, fencing, access control, lighting, identification, communications and surveillance. The Coast Guard is the lead federal agency for maritime homeland security; through the local Area Maritime Security Committee, the Captain of the Port develops a Port Security Plan, and the Coast Guard sets Maritime Security (MARSEC) levels. HDOT’s own Harbor Police patrol the State’s commercial harbors by vehicle and boat (Honolulu Harbor 2050 Master Plan).

The federal rules behind those layers are public. Facility owners must designate a Facility Security Officer, hold a security drill at least every three months and an exercise at least once each calendar year with no more than 18 months between them, and keep anyone without a valid Transportation Worker Identification Credential (TWIC) out of secure areas unless escorted (33 CFR Part 105). Area Maritime Security Committees work under a written charter and meet at least once a calendar year (33 CFR Part 103).

TWIC is where port security meets insider risk. The Transportation Security Administration runs a background check before issuing the credential, and it publishes a canceled card list, updated daily, so facility operators can tell whether a card is still valid; the list includes cards revoked after recurrent vetting (TSA). A credential confirms a check was passed at a point in time. It does not replace a program that watches for changes in behavior or access after hiring, which is the gap ISPI’s analysis of insider threat at Fiji’s ports and PB-07 on supply chain insider risk examine.

Cyber is the newest layer. The master plan notes that the harbor depends heavily on information and operational technology within a just-in-time supply chain, but says the plan itself is not the vehicle for cybersecurity planning (Honolulu Harbor 2050 Master Plan). Federal rules now fill part of that space. The Coast Guard’s final rule on cybersecurity in the Marine Transportation System took effect July 16, 2025 for facilities regulated under the Maritime Transportation Security Act; reportable cyber incidents have had to be reported to the National Response Center since that date, personnel training was due by Jan. 12, 2026, and owners and operators must designate a Cybersecurity Officer, complete an assessment and submit a Cybersecurity Plan by July 16, 2027 (U.S. Coast Guard; Federal Register, Jan. 17, 2025; 33 CFR Part 101, Subpart F). ISPI’s free cyber continuity checklist can help agencies that depend on the port plan for the same scenario.

Border and biosecurity checks happen at the same docks. The plan reports that U.S. Customs and Border Protection screens 100 percent of international cargo through manifest screening, vessel inspection and X-ray and radiation detection, while state and federal agriculture inspectors screen incoming agricultural cargo (Honolulu Harbor 2050 Master Plan). Our explainer on Hawaiʻi’s biosecurity law covers how the State is reorganizing that work.

Gaps the State’s own plan identifies

Three gaps in the master plan are worth tracking, because each is a planning choice rather than a law of geography (Honolulu Harbor 2050 Master Plan; U.S. Army Corps of Engineers):

• Marine firefighting. The plan reports that HDOT does not maintain dedicated marine firefighting personnel or equipment, that the State fireboat was taken out of service in 2014 with no plan at the time to replace it, and that the Honolulu Fire Department lacks the specialized training that shipboard fires require.
• A second entrance. Reopening Kalihi Channel to larger vessels depends on the Army Corps feasibility study and on replacing the fixed Sand Island bridge, for which the master plan sets out several alternatives.
• Cybersecurity planning. The plan leaves maritime cybersecurity plans to the maritime community in coordination with federal and state agencies.

ISPI did not find a public HDOT or Army Corps document reporting that any of these gaps has been closed, or a published final feasibility report. The master plan is dated November 2022, so readers should check with HDOT for current status. We will update this post when either agency publishes changes.

What this means for island and coastal governments

Honolulu Harbor is a well-resourced U.S. port inside a federal security regime, and it still has one usable entrance channel. Island and coastal governments that run their main port with fewer resources face the same structural question. Outside the United States, the equivalent baseline is the International Ship and Port Facility Security (ISPS) Code, in force under SOLAS chapter XI-2 since July 1, 2004, which requires port facility security officers, security assessments and plans (IMO). The ISPS Code covers security. It does not tell a government how long its people can last if the harbor closes.

• Map the single points. List the entrance channel, the main container yard and its bridge or road, the fuel mooring, the jet fuel manifold and the interisland link. For each, record who decides to close and reopen it, and how long a repair or debris clearance has taken in the past.
• Know the clock. Grocery interviews in the master plan suggest about a week and a half of food on shelves, and Lānaʻi waited from the storm until a special barge on Sept. 13 for goods and fuel. Public stockpile advice, such as the two-week guidance in Hawaiʻi, should match the time it realistically takes to reopen the port.
• Pre-position recovery capacity. In 2026, side-scan sonar, divers and cranes cleared the water at Kaumālapaʻu, and Honolulu’s reopening waited on the entrance buoys. Islands without these assets on hand need standing agreements with whoever has them.
• Designate a resiliency pier. Choose a berth near the entrance, harden it, and say in advance which relief cargo gets priority.
• Treat credentials as a start, not the end. Pair port identity cards with an insider risk program that covers contractors, stevedores and customs staff.
• Exercise the whole chain. Run port closure exercises with the harbor master, coast guard or maritime authority, customs, fuel suppliers, interisland carriers and the emergency management agency at the same table.

These questions run through ISPI’s wider work: WP-06 on island supply chain security, the Red Hill water security explainer on another single-source dependency on Oʻahu, our undersea cables explainer, and our Hawaiʻi research hub. ISPI also maps how supply chain singularity plays out on islands worldwide.

Frequently asked questions

What share of Hawaiʻi’s goods come through its harbors?

HDOT’s Honolulu Harbor 2050 Master Plan says about 85 percent of goods used in Hawaiʻi are imported and 91 percent of those imports come through the State’s commercial harbors. Crude oil, which arrives through an offshore mooring, is excluded from that figure.

Does Honolulu Harbor have more than one entrance?

Not for ships. The Main Entrance Channel is the only access for ship transit. Kalihi Channel is blocked to ship traffic by a fixed bridge to Sand Island, and only small vessels can use it. The master plan recommends a feasibility study on reopening it.

Why did Honolulu Harbor close after Hurricane Lowell?

HDOT reported that the harbor was closed because of broken buoys at the harbor entrance. The Coast Guard Captain of the Port reopened it at 9:30 a.m. on Sept. 9, 2026.

Who decides when a Hawaiʻi harbor closes or reopens after a storm?

The U.S. Coast Guard Captain of the Port. HDOT’s Lowell updates report each reopening as a Captain of the Port decision, and the master plan says the Coast Guard decides whether a harbor evacuation is needed and when it is safe to return.

What is a TWIC card?

The Transportation Worker Identification Credential is required under the Maritime Transportation Security Act for workers who need unescorted access to secure areas of regulated maritime facilities and vessels. TSA runs a background check before issuing it and publishes a daily list of canceled cards.

ISPI publishes its research free under CC BY 4.0. If your government, agency or organization needs a port dependency assessment, a port closure exercise, or a briefing on maritime security and insider risk at port facilities, you can commission research from ISPI. ISPI is a nonprofit organization; its application for 501(c)(3) tax-exempt status is pending. Contributions are not tax-deductible until IRS recognition is granted.

Sources

1. Hawaiʻi Department of Transportation, Harbors Division, Honolulu Harbor 2050 Master Plan, Volume I (final, November 2022) (PDF)
2. Hawaiʻi Department of Transportation, Harbors Division, 2024 Title VI Program Plan (PDF)
3. Hawaiʻi Department of Transportation, HDOT updates on transportation infrastructure following Hurricane Lowell, September 8, 2026
4. Hawaiʻi Department of Transportation, Sept. 9 updates on road, harbor restoration after Lowell, September 9, 2026
5. Hawaiʻi Department of Transportation, Kaumālapaʻu Harbor will be ready for operations Sunday, Sept. 13, September 10, 2026
6. Hawaiʻi Department of Transportation, Limited access to Kaumālapaʻu Harbor Sunday, Sept. 13, September 12, 2026
7. Hawaiʻi Department of Transportation, Weather related traffic alerts (facility status, viewed October 31, 2026)
8. Hawaiʻi Department of Transportation, HDOT receives $40.1 million federal grant for Port of Kahului, October 27, 2026
9. Hawaiʻi Emergency Management Agency, 2-Weeks Ready in Hawaiʻi
10. Electronic Code of Federal Regulations, 33 CFR Part 105, Maritime Security: Facilities (sections 105.205, 105.220, 105.255)
11. Electronic Code of Federal Regulations, 33 CFR Part 103, Maritime Security: Area Maritime Security (section 103.300)
12. Electronic Code of Federal Regulations, 33 CFR Part 101, Subpart F, Cybersecurity
13. U.S. Coast Guard, Cybersecurity in the Marine Transportation System, final rule, 90 FR 6298, Federal Register, January 17, 2025
14. U.S. Coast Guard Maritime Commons, Final Rule: Cybersecurity in the Marine Transportation System, Implementation Timeline, July 16, 2025
15. Transportation Security Administration, TWIC
16. U.S. Army Corps of Engineers, Honolulu District, Honolulu Deep-Draft Harbor Modification (civil works project page)
17. International Maritime Organization, SOLAS XI-2 and the ISPS Code
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