When tankers come under threat in a busy shipping lane, the first headlines are usually about oil prices. Behind the scenes, though, a quieter cost starts to climb: the price of insuring a ship for the voyage. War-risk insurance is one of the less visible ways that conflict feeds into energy markets, and it helps explain why tension at sea can matter even when oil keeps flowing.
What the cover is for
Ordinary marine insurance protects ships against everyday risks such as collisions, bad weather and mechanical failure. It generally excludes damage caused by war, attacks, mines or seizure. Those risks are covered separately by war-risk insurance.
For most of the world’s sea routes, war-risk cover is a small part of a voyage’s cost. In areas marked as high risk, it can become much more significant. Insurers can charge an additional premium for each trip through a designated zone, usually calculated as a percentage of the ship’s value.
Why the premium changes so quickly
War-risk premiums respond to events almost in real time. When attacks on shipping increase, insurers reassess the danger and raise their rates, sometimes within days. When things calm down, rates can ease, though often more slowly than they rose.
Because the premium is linked to the value of the ship, the cost of insuring a large modern tanker for a single passage through a dangerous area can become substantial. That cost has to be absorbed by someone, whether the shipowner, the charterer or, eventually, the buyer of the cargo.
Why the Strait of Hormuz is central
The Strait of Hormuz is a narrow channel between Iran and Oman, and a large share of the world’s seaborne oil passes through it. Our explainer on Strait of Hormuz oil risk sets out why it matters so much.
Recent reports of tankers being struck or turned back in the area are exactly the kind of events that push insurers to reprice. Even if oil continues to move, a higher cost of passage changes the economics of each voyage.
How it feeds into oil prices
War-risk insurance affects oil markets in a few ways.
It raises delivered costs. Higher insurance adds to the total cost of getting a barrel from the producer to the refinery, which can widen the gap between prices in different regions.
It can deter some shipping. If premiums become very high, or cover becomes hard to obtain, some owners may choose to avoid a route altogether. That can tighten available shipping capacity and push up freight rates, a link covered in our guide to how shipping freight rates connect to oil shocks.
It acts as a sentiment gauge. Traders sometimes watch reports on insurance costs as a signal of how seriously the industry is taking the threat. Rising premiums suggest the people with money at stake see a real danger.
How it interacts with emergency supply
Governments have tools to soften supply shocks, including releasing oil from strategic reserves. A coordinated release, such as the one recently agreed by the G7, can help ease concerns about immediate shortages. It does not change the cost or risk of moving oil through a dangerous waterway, though. That is why markets can weigh both at once: reassurance on supply, alongside lingering worries about transport.
It is also why it is unwise to describe the oil market in a single word. Different benchmarks and different routes can respond in different ways, depending on how directly they are exposed.
What traders can take from it
For a trader, war-risk insurance is not a number you trade directly, but it is useful context. It helps explain why oil can stay sensitive to shipping news even when supply appears adequate, and why calm on one day does not necessarily mean risk has gone away. Headlines in this area can move quickly, so position sizes should allow for sudden swings.
If you would like a more structured way to handle headline-driven markets like this, our free trader assessment can help you see how well your current process copes with fast-moving news.
