Why optimised voyages don't always deliver: the Maritime Execution Gap

Despite billions invested in route planning, weather routing and speed optimisation, vessel performance still falls short of what tools predict on paper. This first insight in our 12-part series introduces what we call the ‘execution gap’, the difference between optimised plans and what actually happens once a vessel leaves the berth, and why closing it has become the central efficiency challenge facing shipping in 2026.

Operational optimisation is an essential feature of modern maritime shipping. There have been advances in data availability, vessel performance modelling, and weather forecasting over the past decade, enabling operators to plan voyages with greater precision.

Route optimisation, speed recommendations, and fuel performance analysis are used throughout the industry to improve efficiency, reduce emissions, and enhance commercial outcomes. These tools are now widely embedded within fleet operations and are often supported by both onboard systems and shore-based performance teams.

Despite the advancements made, the industry is now facing another challenge. While optimisation capabilities have improved, vessel performance can fall short of the levels predicted on paper. Voyage plans that appear optimal at the planning stage are not always executed as planned once real-world operating conditions and human factors are introduced.

This creates a gap between projected and actual performance that becomes more pronounced on longer, more complex voyages. This separation is referred to as the ‘execution gap’ in this report, and is emerging as a central barrier to further efficiency gains in shipping.

In this context, the ability to consistently execute optimisation strategies is becoming as important as the strategies themselves. Simultaneously, many operators have already implemented the most accessible optimisation measures. The industry, therefore, appears to be entering a phase in which further gains are smaller and somewhat dependent on consistent execution rather than on improved planning.

Penny Haire, CEO of Tidetech, described a common shipping practice in which vessels use a tactic known as ‘sprint and loiter’ to avoid late-arrival fees.

Haire provided the example of a vessel making a voyage across the Atlantic Ocean towards northern Europe, under pressure to arrive on time. Missing a pilot slot can be costly, so crews often see the safest commercial decision as pushing harder early in the voyage.

However, if the ship arrives too early, it may spend hours waiting at anchor, having burnt through more fuel than necessary. “Crew will tend to put the hammer down early, then when they get there, they might be half a day early, so they anchor,” explained Haire.

This is a familiar operational scenario for crew, and it showcases one of the central contradictions in maritime optimisation. While a voyage plan might look efficient on paper, once commercial pressures, uncertainty, and real-world operating conditions take hold, execution becomes less straightforward.

This uncertainty is built into the operating environment itself. As Erkut Denizci, Fleet Manager at ITM, put it, “regardless of the technological developments, there is no technology available that can predict the whole voyage into the minor detail in advance.” This explains why navigation is not only a science but also an art bridge teams should practice in order to achieve operational goals.

This problem, known as the execution gap, matters more in 2026 than previously due to a host of factors, with regulatory pressure a central one. For example, operational carbon intensity requirements (CII) and energy efficiency requirements (EEXI) have made performance essential to compliance and reputation.

Download ‘Precision In Motion’ and discover how supervised speed automation can help close the gap between what is planned and what is actually delivered onboard.