Maritime Accidents and Incidents: Number, Types and Location - Desteia

Maritime Accidents and Incidents: Number, Types and Location

Maritime incidents are a common phenomenon in the world of logistics. In this essay, we quantify just how common they truly are.

Jose Luis Sabau
February 17, 2025
Macro

Maritime incidents are the bread and butter of the logistics world. After a year like 2024, plagued with disruptions and unforeseen events, operators have grown accustomed to ships encountering problems at sea—be it a hurricane closing ports or pirates attacking cargo ships. The question, however, is how likely it is that any given vessel will be subject to an incident?

Our analysis—which we will examine further in this paper—suggests that around 2.61% of the global shipping fleet today was subject to at least one incident in the last decade.

But, let’s start with the basics. Ocean incidents, from flooding and collisions to fires and mechanical difficulties, are, indeed, extremely common. The International Maritime Organization (IMO) has a thorough registry of all incidents over the last years which we used across this paper to determine the true magnitude of this phenomenon. Just how common are these incidents? Well, over the last decade (between 2015 and 2024) the IMO registered 2,935 incidents at sea. That comes down to about an incident every other day for the period examined—0.8 incidents per day, but, since vessels don’t exist in fractions, we will keep the above statement to be accurate.

We know that, as of 2024, the total number of vessels at sea was an estimate of 109,000—including non-cargo and cargo vessels alike. According to IMO data, the 2,935 incidents registered over the last decade involved 3,352 vessels—of which, 2,849 were unique vessels, thus suggesting there were, at most, 503 vessels with at least two incidents. This, in turn, implies that, over the last decade, roughly 2.61% of vessels in the global fleet have suffered at least one accident.

In the figure below, we plotted the precise location of all maritime incidents over the last decade. The color of each point, as shown in the accompanying legend, indicates whether it was a small incident (Marine Incident), a casualty (Marine Casualty), or a severe incident with casualties (Very serious marine casualty). If you hover your mouse over any figure, it will show further information on the incident, including its date and location.

Maritime Accidents by Severity

Maritime Accidents by Severity (2015-2024)

A map showing the location of all maritime incidents over the last decade.

Source: IMO
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Created with Datawrapper

Additionally, as one can notice from the color of each dot in the map, there does seem to be a tendency towards very severe incidents. In the pie chart below, we divided the total incidents by their severity. As the figure shows, 61.87% of all incidents in the examined period were considered “very serious marine casualties” by the IMO. These were followed by non-serious casualties (28.96%) and lower-level incidents (9.17%).

Maritime Incidents by Severity

(between 2015 and 2024)

A pie chart showing maritime incidents between 2015 and 2024 by severity.

Source: IMO
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Created with Datawrapper

We can further look at geographic data from the IMO to determine the location of each incident relative to existing infrastructure. As we show in the figure below, the bulk of incidents happen out at sea, with 26.31% occurring in open waters, and an additional 24.87% occurring in coastal waters—together accounting for over half of all occurrences. These were, in turn, followed by incidents at port with 18.74% of occurrences.

Maritime Incidents by Location

Maritime Incidents by General Location

A pie chart showing the general location of all maritime incidents over the last decade.

Source: IMO
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Created with Datawrapper

The IMO also provides important information on the specifics of each incident which allows us to understand the most common issues impacting the global shipping fleet. In the figure below, we plotted each of the official categories registered by the IMO for maritime incidents. As one can see, these categories are extremely specific, giving a more accurate depiction of problems at sea. By far, the most common category was contact with some form of fixed object—i.e., a collision—which represents 139 of all incidents over the last decade. These were followed by groundings (85 instances) and occupational incidents (84 occurrences). Although it is worth noting that no single category accounts for over 5% of incidents in the examined period.

Maritime Incidents by Type

Maritime Incidents by Type (2015-2024)

A bar chart showing maritime incidents between 2015 and 2024 by type.

Source: IMO
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Created with Datawrapper

It is worth noting that, in recent years, incidents have become less and less common. In the figure below, we plotted the total number of incidents registered in any given year. As we can see from the graph, there has been a sharp decline in incidents since 2017, when the IMO registered the highest number of incidents of the decade: 460. By 2023, the number had fallen to just 236—data for 2024 hasn't been updated since June of that year.

Number of Maritime Incidents per Year

Number of Maritime Incidents per Year (2015-2024)

A line graph showing the number of maritime incidents per year between 2015 and 2024.

Occurrences

Source: IMO
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Created with Datawrapper

Now that we are speaking of time trends, it is worth digging deeper into IMO data to draw useful conclusions for logistics operators. More specifically, we’d be interested in showing which are the most common dates in which incidents occur. To do so, we designed two graphs which we share below.

First, in the following graph, we divided the incidents observed by the month in which they took place. As the graph shows, there are two important bumps in the data: one in February and one in August. These would roughly align with heavy traffic periods for logistics such as Chinese New Year, and the summer months as companies prepare shipments for the holiday seasons.

Number of Maritime Incidents per Month

Number of Maritime Incidents per Month

(total incidents in that month between 2015 and 2024)

A bar graph showing the total number of maritime incidents over the last decade by month.

Source: IMO
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Created with Datawrapper

Second, in the subsequent figure, we did the same analysis as above but, instead of disaggregating data by month, we did it by the hour in which an incident was registered. As the figure shows, there is a sharp increase at midnight, which is likely a result of internal records being updated at the end of each day—but that is a mere hypothesis. Besides that drastic increase, we also see considerable peaks around 9 am and 1 pm—which might correlate to busy periods at ports.

Number of Maritime Incidents per Hour

Number of Maritime Incidents per Hour

(total incidents in that hour between 2015 and 2024)

A bar graph showing the total number of maritime incidents over the last decade by the hour in which they took place.

Source: IMO
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Created with Datawrapper

Finally, tapping into one additional element of IMO data, we were able to identify the countries that are most prone to file incidents with the organization. In the map below, the color of each country indicates how many reports each country filed over the last decade. Colors close to purple indicate the country filed more reports with the IMO while those closer to yellow indicate the country filed fewer reports. As the data shows, Panama was the country that filed the most reports with 187, followed by the UK with 107.

Number of Maritime Incident Investigation Reports by Country

Number of Maritime Incident Investigation Reports Filled by Country

(filled between 2015 and 2024)

A heat map showing the number of investigation reports filled by each country by the IMO between 2015 and 2024.

Source: IMO
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Created with Datawrapper

All the information above suggests that maritime incidents are not just common, but are also complicated. They cannot be easily explained by a handful of theories even though, at least in terms of time and location relative to port, they do follow some important patterns. These details should be taken into consideration by operators when planning routes or designing supply chains for a company.

At Desteia, we leverage data similar to that displayed in this article to help operators identify the impact of their specific use cases.