Why weather is an overlooked performance trap in vessel vetting
When chartering managers are evaluating a vessel, speed is often one of the first things they look at, and it makes sense since speed directly influences voyage duration, fuel consumption, and ultimately P&L.
But speed derived from AIS alone rarely tells the full story. More often than not, it leaves charterers with the question on how the vessel’s speed behaved in different weather conditions to understand if it meets the owner’s description.
Not always comparing apples to apples
If we look at two vessels trading similar routes, where one appears to have a much stronger performance record than the other, the decision can seem straightforward. However, vessel performance is heavily influenced by the conditions a ship encounters during its voyages. Sea state, swell, and weather patterns can all affect speed, meaning historical performance figures do not always provide a like-for-like comparison.
Historically, weather has largely been viewed as a post-fixture consideration. It helps explain why a vessel lost speed, experienced delays, or deviated from expectations during a voyage. But by the time those conversations happen, the fixture has already been concluded and the decision made.
Bringing weather into the decision-making process
The question is becoming increasingly relevant as weather patterns grow more volatile. A vessel trading through rough seas may appear slower than another operating in calmer waters, even if it’s performing exactly as expected. At the same time, a vessel that appears attractive based on historical averages may simply be benefiting from more favorable conditions.
For charterers, that distinction matters. Every additional day at sea has a cost. Longer voyage durations increase exposure and erode margins. The challenge is determining whether that risk comes from the vessel itself or the conditions it encountered.
A fairer way to compare vessel performance
This is where weather context can improve vessel vetting. Rather than simply looking at what happened after a voyage, charterers can see why it happened, creating a fairer basis for comparing vessels and identifying potential risks.
That’s why earlier this year we introduced weather insights into our Pre-Vetting solution. By incorporating weather-adjusted performance analysis and sea-state context into vessel screening data, our aim is to give charterers a clearer view of a vessel's true operating potential and commercial exposure before fixing.
The bottom line is that when it comes to protecting margins, better decisions do not always require more data. They require better context.
Want to see what Pre-Vetting can do for your chartering activities? Get in touch to learn more