Short, practical reads from real fleet work — published here first, then shared on LinkedIn.
Five families of efficiency measures, sorted by where they do their work between the fuel tank and the delivered cargo, plus the three questions that show what any vendor's savings claim is really made of.
Fluid mud recreates Nansen's dead-water mystery in modern ports: internal waves, yield-stress drag, and a seabed defined by density, not the echo sounder.
In open water a ship's waves leave forever. In a canal they reflect off the banks and return to the hull — added resistance governed by the blockage ratio.
In shallow water waves cannot outrun √(g·h). As the depth Froude number nears 1.0 resistance spikes — and the trap starts at normal service speed.
Near a canal bank the bow is pushed off and the stern pulled in — a yaw moment that scales with speed squared. The physics behind the NTSB Genesis River case.
In shallow water the flow accelerates under the hull and pressure drops — the ship sinks bodily and trims, full forms by the bow and fine forms by the stern. Why squat is a resistance problem, not just a safety margin.
Rivers, channels, and port approaches play by different rules than open water. Five hydrodynamic effects — squat, bank effect, critical speed, wave deformation, and mud — reshape resistance, power demand, and safety margins.
Currents alter the very water a ship sails through: head currents force a higher speed through water, and cross-currents force a drift angle — both quietly inflating fuel consumption.
Heavy weather penalizes a ship twice — once through wind and wave drag, and again through the rudder corrections needed to hold course. Steering drag grows with the square of rudder angle, and an over-tuned autopilot can quietly add 3–10% to fuel consumption.
In long waves a pitching ship becomes a wave-maker of its own — radiating energy stolen straight from the propeller's thrust. In a Beaufort 6 sea, wave radiation alone can exceed 20% of total resistance.
Before a ship ever pitches or heaves, it loses energy to wave diffraction — short waves shattering against the bow act as an invisible hydrodynamic brake, even when the vessel feels perfectly stable.
Wind drag scales with the square of apparent wind speed — so headwinds punish fuel consumption far more than tailwinds help. Phase 2 of the vessel resistance series looks at the physics, and why wind correction decides whether your data blames the weather or the hull.
Wrapping up the calm-water resistance series and opening Phase 2 — added weather resistance, where the real fuel bill is decided.
Two underestimated sources of drag: underwater appendages (bilge keels, rudders, shafts) and the cost of steering.
Even on a dead-calm sea, moving forward creates an apparent headwind. Why air resistance matters even without weather.
The localised drag at the stern: how pressure recovery along the hull (or the lack of it) creates viscous pressure resistance.
How a ship's hull generates a system of gravity waves as it advances — and why wave-making resistance is a key driver of efficiency.
A technical look at frictional resistance — the ITTC-57 correlation line, Reynolds number, boundary layers, and why it dominates calm-water drag.
Frictional resistance is one of the most underestimated drivers of inefficiency — and why fouling is a performance issue, not just a maintenance one.
Even in calm water, hidden forces fight a ship's progress. A breakdown of the five fundamental components of total resistance.
Is your vessel performance data an asset or a liability? Why data quality is the foundation of compliance in modern shipping.
Poor hull and propeller performance is an underestimated cost drain — ISO 19030 gives operators a disciplined, data-driven way to measure and manage it.
High-quality data is the only foundation for reliable insight — and that takes engineered data pipelines, not just collection.
Hull fouling quietly raises fuel consumption, cuts speed, and undermines compliance — a challenge for technical managers, owners, and charterers alike.
Continuous vessel monitoring is shifting from a nice-to-have to a commercial necessity for performance and decarbonisation.
An article on why energy efficiency in shipping is as much about culture and habits as it is about technology — and how fleet data helps build that culture.