On November 30, 2020, the container ship ONE Apus lost roughly 1,816 containers overboard in a Pacific storm en route from Yantian to Long Beach. It remains the largest single vessel container loss in recent history. Cargo damages were estimated above $200 million. Insurance, salvage, and general average claims took years to settle.
Container losses overboard are rare relative to the volume of boxes shipped each year, but they are not random. The same conditions show up repeatedly across major incidents: heavy seas, parametric rolling, securing failures, mis declared cargo weight, lashing system fatigue, and fires that start in mis declared dangerous goods. For freight forwarders, every loss is a chain of contract, insurance, customs, and claims work that lasts for months or years.
This guide walks through the ONE Apus incident and the other large container loss events of the last decade, explains the engineering and operational causes, breaks down the insurance and general average exposure forwarders face, and lays out the controls that meaningfully reduce risk on every booking.
Container loss at sea covers any incident where boxes leave the deck or hold of a ship and end up in the water, on the seabed, or washed up on shore. Most losses are containers washed overboard from deck stacks in heavy weather. A smaller share comes from vessel sinking, fire and total loss, structural failure of the ship, or collision and grounding events. The headline figure for any year is the sum of all of these.
Two reference sources track the numbers. The World Shipping Council (WSC) publishes an annual Containers Lost at Sea report based on member carrier disclosures, which covers most of the global fleet. The TT Club, a major maritime insurer, publishes its own loss and claims analysis. Both data sets show year to year variance driven by a small number of large events. A single severe incident like the ONE Apus or the MSC Zoe can swing the annual total by 1,000 or more boxes on its own.
For context, the global container fleet moves roughly 250 million container movements per year. WSC data through 2024 puts the rolling average loss at about 1,000 to 1,500 boxes per year, a meaningful reduction from the 2,300 plus average across 2020 to 2022 that the ONE Apus year pushed up. The loss rate as a share of containers shipped sits around 0.0001 percent. Rare, but concentrated in a way that makes any single voyage on a specific lane materially riskier than the headline average suggests. Forwarders running booked volume through modern Ocean Freight Management Software can at least see which voyages and lanes they are exposed to, which is the starting point for any risk conversation with a customer.
The ONE Apus is a 14,000 TEU class container ship operated by Ocean Network Express (ONE), the Japanese carrier formed by the 2018 merger of NYK, MOL, and K Line container divisions. The November 2020 voyage was a routine Yantian to Long Beach transpacific sailing.
On November 30, 2020, the vessel encountered severe weather in the North Pacific. The official ONE statement described violent stormy weather with very heavy seas and a sustained period of heavy rolling. The combination caused container stacks on deck to collapse and tip overboard. The ship diverted to the port of Kobe, Japan, for damage assessment and cargo recovery work.
Final accounting put the loss at approximately 1,816 containers, of which 64 were declared as containing dangerous goods. Initial cargo damage estimates ran above $200 million across the affected shippers. General Average was declared by ONE in early December 2020, which meant every cargo owner with goods on board, whether their containers were lost or intact, became liable for a proportional share of the salvage and recovery costs. Cargo without insurance was held until owners posted bond.
The ONE Apus incident is now the canonical case used by insurers and naval architects when illustrating the magnitude of risk in modern ultra large container ship operations. It is also why the post 2020 industry conversation moved heavily toward parametric rolling research, lashing standards review, and VGM enforcement.
The ONE Apus was the largest, but it was not the first or the last. The table below lists the major container loss and total loss events of the last fifteen years, with the estimated loss count and the documented or suspected root cause for each.
| Year | Vessel | Containers Lost | Root Cause |
|---|---|---|---|
| 2013 | MOL Comfort | ~4,293 (total loss) | Hull broke in two amidships in heavy weather in the Indian Ocean. Vessel sank with all cargo. Structural failure traced to hull strength and loading distribution issues. |
| 2018 | Maersk Honam | ~2,500 damaged or destroyed | Catastrophic fire in cargo hold in the Arabian Sea. Five crew died. Suspected source mis declared dangerous goods. General Average declared. |
| 2019 | MSC Zoe | ~342 | Heavy weather over shallow North Sea waters north of the Wadden Islands. Parametric rolling and contact with seabed in shallow draft caused stack collapse. Months of beach cleanup along Dutch and German coasts. |
| 2020 | ONE Apus | ~1,816 | Violent Pacific storm. Parametric rolling and stack collapse. Largest single vessel loss in recent history. General Average declared. |
| 2021 | Maersk Essen | ~750 | North Pacific weather event en route Xiamen to Los Angeles. Heavy rolling and stack collapse. Diverted to Mexico for damage assessment. |
| 2021 | X-Press Pearl | ~1,486 (total loss) | Fire and sinking off Colombo, Sri Lanka. Source traced to nitric acid leak from a mis declared container. One of the worst marine environmental disasters in South Asian waters. |
| 2021 | ZIM Kingston | ~109 plus on board fire | Heavy seas off Victoria, British Columbia, followed by on board fire in dangerous goods containers. Combined weather and DG event. |
| 2024 | President Eisenhower | ~24 | Heavy weather off the US West Coast. Smaller loss event, illustrative that the pattern continues at lower magnitude in calmer years. |
The pattern across all of these is consistent. Heavy weather plus parametric rolling causes stack failures. Mis declared dangerous goods cause fires. Hull or structural failure on its own is rarer in the modern fleet but is still the cause of the single largest total loss event on the list (MOL Comfort, 2013).
Container stacks on the deck of a modern Ultra Large Container Vessel (ULCV) can rise eight or nine boxes high above the hatch covers. Those stacks are held in place by twistlocks, lashing rods, turnbuckles, and the strength of the containers themselves. The system is engineered for a specified range of vessel motion. When the vessel exceeds that range, the system fails.
Parametric rolling is the single most cited cause of large stack collapse events. It is a dynamic instability that happens when the wave encounter period lines up with the ship's natural roll period. The vessel begins to roll heavily even in moderate seas. On large container ships with high above deck stacks and bow flare characteristics that affect restoring forces, parametric rolls of 30 to 40 degrees can develop in minutes. Stack collapse follows almost immediately.
The MSC Zoe and ONE Apus events are widely cited examples of parametric rolling in different sea states. Naval architecture research since 2020 has focused on early detection algorithms and route guidance to keep ULCVs out of conditions that produce the resonance.
Even without parametric rolling, securing systems fatigue over time. Twistlocks wear, lashing rods stretch, turnbuckles loosen. A lashing system that performs to spec on day one may not perform to spec at year five if maintenance has lagged. Class society inspections cover this, but real time condition is harder to know.
The IMO Verified Gross Mass (VGM) rule, in force since 2016, requires the shipper to provide a verified weight for every loaded export container before it can be loaded on a ship. Mis declared or under declared VGM throws off the stowage plan. Heavier than declared containers placed in upper tiers raise the center of gravity and increase the risk of parametric rolling and stack failure. WSC data shows VGM compliance has improved since 2016 but is not universal.
Dangerous goods that are not declared or are mis declared are the leading cause of the catastrophic fire events on the list above. Lithium ion batteries, charcoal, calcium hypochlorite, and nitric acid are recurring offenders. The CINS network (Cargo Incident Notification System) data has shown for years that DG mis declaration is a chronic, systemic risk that no carrier or insurer has fully solved.
Rare in the modern fleet but not unheard of. The MOL Comfort breaking in two in 2013 prompted a class society review of ULCV hull strength standards. Modern post 2015 ULCV designs incorporate the lessons. Older or modified vessels remain a tail risk on certain trades.
For a forwarder, the insurance and claims work after a loss event is usually the most painful operational layer. Two structures matter most.
Marine cargo policies are usually written against the Institute Cargo Clauses, which come in three tiers: (A) All Risks, (B) Named Perils, and (C) Limited Named Perils. Most shippers and forwarders carry ICC (A) on high value or fragile cargo because it covers physical loss or damage from any external cause unless specifically excluded. ICC (B) and (C) are cheaper but exclude many of the failure modes seen in loss events.
A container that goes overboard and is irretrievable is a total loss claim under ICC (A). A container that survives the voyage on a vessel that suffered loss is usually a partial loss or general average claim, which is a different process.
General Average is a centuries old principle of maritime law. When the ship's master takes an extraordinary action to save the voyage (jettisoning cargo, diverting for salvage, fighting a fire), the costs are shared by every cargo owner on board in proportion to the value of their cargo. A container that arrived intact at the destination port can still be subject to a six or seven figure general average claim if the vessel declared GA on the voyage.
The mechanics work as follows. When GA is declared, the carrier issues a General Average Bond requirement. Cargo owners cannot collect their containers until they either post a cash deposit (often 10 to 50 percent of cargo value) or provide an insurance Average Guarantee from their cargo insurer. Cargo without insurance has to wire cash. ONE Apus, Maersk Honam, and X-Press Pearl all involved General Average declarations. Settlement of GA claims typically takes one to three years.
This is the single strongest practical argument for ICC (A) marine cargo insurance on every shipment. The premium is small. The avoided exposure on a GA event is large.
Major loss events trigger salvage operations under Lloyd's Open Form or similar contracts. Salvage awards are paid out of the vessel and cargo value, which feeds back into the General Average calculation. Wreck removal for total loss events (MOL Comfort, X-Press Pearl) is separately funded but often disputed for years through litigation.
Forwarders managing claims after a loss event lean heavily on systems that can pull the bill of lading, commercial invoice, packing list, VGM, and DG declaration for every affected shipment into one record. Modern Freight Billing and Accounting Software for Forwarders that holds booking, BL, and document data at the shipment level makes the claims package and the salvage or General Average reconciliation with the customer easier to assemble cleanly the first time.
Beyond the direct cargo loss, container loss events ripple through forwarder operations in several recurring ways.
When a vessel diverts after a loss event, every shipment on that vessel needs an updated ETA, an updated routing, and a customer notification. Most of these events hit US bound cargo on transpacific lanes, which is where Ocean Import Freight Management Software matters, because the consignees are the parties waiting for diversion news and revised discharge port confirmation. Forwarders running container visibility through Shipment Tracking and Operations Software for Forwarders can push the revised ETA from the carrier data feed into the shipment record and out to the customer in a few clicks instead of rebuilding the picture by email for hundreds of shipments.
If General Average is declared, every customer with cargo on the affected voyage needs to be contacted, the GA bond requirement explained, and an insurance Average Guarantee or cash deposit arranged before the container is released at destination. The faster the forwarder can pull commercial invoices and BL data for every affected shipment, the faster customers can post bond and reduce demurrage exposure.
Salvage charges, GA contributions, diversion surcharges, and storage at the diversion port all hit the accounting ledger over the months following the event. Forwarders can match the carrier invoices for each new charge against the original shipment and the customer billing record cleanly on one shipment ledger, instead of treating each as a one off cost outside the shipment record.
Any major loss event on a customer's lane triggers a fresh insurance conversation. Customers who were on ICC (B) or self insured often move to ICC (A) after seeing a peer experience a GA claim. Forwarders who can show customers a clear summary of historical incidents on a lane help anchor the policy upgrade conversation.
The base rate of container loss is low, but the controllable risk for a specific booking is real. Six practical levers move the needle.
Accurate VGM on every export container. Verified Gross Mass is not paperwork. The vessel stowage planner uses the declared weight to build the load. Under declared weight in upper tier stowage materially increases stack failure risk. Discipline at the export shipper level matters.
Strict dangerous goods declaration discipline. Every DG class container needs the correct UN number, packing group, and IMDG documentation. Forwarders should refuse to accept DG bookings without the declaration sheet and the matching marks and labels. CINS data shows mis declaration is the single largest controllable cause of catastrophic fire events.
Marine cargo insurance written to ICC (A) on every shipment. The premium is a small percentage of cargo value. The exposure on a GA event is not. Forwarders should default to ICC (A) marine cover on every booking and require the customer to opt out in writing if they decline. This protects both the customer and the forwarder's claims experience.
Carrier selection on safety, not just price. Carrier fleet age, class society history, and casualty record matter for risk on a given booking. The lowest rate on the market does not always come from the carrier with the strongest safety record. On high value or sensitive cargo the price spread to a safer operator is usually worth it.
Lane and seasonal awareness. Transpacific in November and December and North Sea winter routings carry meaningfully elevated weather risk. Forwarders quoting customers in those windows should price for the extra exposure or recommend alternative timing.
Single shipment record discipline. The hardest part of claims work after an event is reassembling the documentation. Forwarders who hold booking, BL, commercial invoice, VGM, DG declaration, packing list, and insurance certificate in one shipment record close claims faster and with less dispute than those rebuilding paperwork after the fact.
Three signals will shape the loss trend over the next two years.
WSC and TT Club annual loss reports. The annual Containers Lost at Sea report from the World Shipping Council and the TT Club annual claims analysis are the cleanest benchmarks for whether industry wide loss rates are continuing the post 2022 downward trend or whether a new spike year is forming.
IMO and carrier action on lithium ion battery declaration. Lithium battery fires on container ships and pure car carriers have been the fastest growing dangerous goods incident category. Any new IMO rule, carrier surcharge, or refusal policy on lithium cargo will affect quoting and routing decisions on electronics, EV, and consumer goods lanes.
Parametric rolling research and onboard decision tools. Several class societies and naval architecture programs have published parametric rolling early warning systems for ULCVs since 2021. Carrier adoption of these tools, and any visible reduction in heavy weather loss events on transpacific and North Sea routings, will be the strongest evidence that the engineering response to the post 2020 wave of losses is actually working.
The base case for 2026 to 2027 is that the industry loss average continues at or just below the current 1,000 to 1,500 box per year range, punctuated by occasional severe single ship events. The risk case is a fresh combination of a major weather year and a high profile DG fire that pushes the annual total back above 2,000.
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The ONE Apus lost approximately 1,816 containers in a Pacific storm on November 30, 2020, en route from Yantian to Long Beach. It is the largest single vessel container loss in recent history. Cargo damage estimates ran above $200 million and ONE declared General Average in early December 2020.
The World Shipping Council reports an industry average of roughly 1,000 to 1,500 containers lost at sea per year in the most recent period, down from the 2,300 plus average across 2020 to 2022. Against roughly 250 million container movements per year, the loss rate is about 0.0001 percent. Annual totals are volatile because a single severe event can swing the number by 1,000 or more boxes.
The recurring causes across major incidents are parametric rolling in heavy seas, lashing and securing system failures, mis declared cargo weight (VGM), mis declared dangerous goods that trigger on board fires, and in rare cases hull or structural failure. Parametric rolling on ultra large container ships with high above deck stacks is the most cited cause of large stack collapse events.
Parametric rolling is a dynamic instability that develops when the wave encounter period lines up with a ship's natural roll period. On modern ultra large container vessels with high above deck stacks, parametric rolls of 30 to 40 degrees can develop in minutes even in moderate seas. The motion causes container stacks to exceed lashing system limits and collapse. The MSC Zoe and ONE Apus events are widely cited examples.
General Average is a maritime law principle under which the cost of any extraordinary action taken to save a voyage (jettisoning cargo, salvage, fire fighting, diversion) is shared by every cargo owner on board in proportion to the value of their cargo. A container that arrived intact can still face a six or seven figure General Average claim if GA was declared on the voyage. Cargo owners without marine insurance must post a cash bond before containers are released. ICC (A) marine cargo insurance covers GA contributions and is the strongest argument for carrying it on every shipment.
Some are. Containers in shallow water, washed up on shore, or floating intact are often recovered through salvage operations. Containers that sink in deep ocean water rarely are. Recovery work after the MSC Zoe in 2019 involved months of beach cleanup along the Dutch and German coasts. Deep water losses such as those from the ONE Apus and MOL Comfort are essentially unrecoverable.
Verified Gross Mass (VGM) is the IMO required declaration of the total weight of a loaded export container, in force since 2016. The vessel stowage planner uses the declared weight to build the load. Under declared weight in upper tier deck stowage raises the vessel's center of gravity and increases parametric rolling and stack failure risk. Accurate VGM at the export shipper level is one of the highest leverage controls a forwarder can enforce.
CINS network data and incident reports show lithium ion batteries, charcoal, calcium hypochlorite, and nitric acid as recurring offenders in catastrophic container ship fires. Mis declared or undeclared dangerous goods are the leading cause of the major fire events seen in recent years, including Maersk Honam in 2018 and X-Press Pearl in 2021. Strict declaration discipline and refusal to load undocumented DG bookings is the primary control.
Marine cargo insurance written to the Institute Cargo Clauses (A) is the standard recommendation. ICC (A) is All Risks cover that protects against physical loss or damage from any external cause unless specifically excluded, including total loss from a container going overboard and General Average contributions when GA is declared on the voyage. Forwarders should default to ICC (A) cover on every booking and require customers to opt out in writing if they decline.
The highest leverage controls are accurate Verified Gross Mass (VGM) on every export container, strict dangerous goods declaration discipline with refusal of undocumented DG bookings, default ICC (A) marine cargo insurance on every shipment, carrier selection that weighs safety record and fleet age alongside price, seasonal and lane awareness for known high risk routings, and keeping booking, BL, VGM, DG, and insurance documents in a single shipment record so claims documentation is ready before an event happens.