Vessel Performance Monitoring: Noon Reports vs High-Frequency Data

The two data regimes

Fuel is the largest variable cost in shipping and, since EU ETS and FuelEU Maritime attached a price to emissions, it is also a compliance cost. Everything about how a ship is driven and maintained now flows through one question: how much energy did it take to move this ship, and was that reasonable?

Answering it requires performance data. There are two schools, and they are not equivalent.

A noon report tells you the ship burned 24.6 tonnes yesterday. It cannot tell you that eleven of those hours were at excessive shaft power to make a berthing window, or that the fuel meter drifts 3% at low load.

What high-frequency data actually reveals

Hull and propeller degradation. Fouling develops continuously. Speed loss versus a reference curve is a smooth, rising line — with a step change when the ship idles in warm water. Noon reports show this only after it becomes severe.

Engine condition drift. Specific fuel oil consumption trending upward at constant load, before any alarm.

Operational waste. Speeding up to arrive and wait. The single largest avoidable fuel cost in most fleets, and invisible in daily averages.

Meter integrity. Cross-checking flow meters against tank soundings and bunker delivery notes catches drift — which matters, because those meters now feed a regulatory calculation with a cash cost.

Figures are indicative ranges from published industry practice; actual savings depend heavily on trade, hull condition and baseline discipline. The point of the chart is the ranking, not the decimals.

Weather correction: the part that decides arguments

Raw consumption comparisons are worthless without weather correction. Two vessels on the same route in the same week can experience materially different conditions, and every charterparty performance dispute turns on the definition of "good weather" and on whose weather data is authoritative.

Good practice:

• Agree the weather data provider in the charterparty
• Define good weather precisely: sea state, wind force, current, swell
• Correct for draft and trim, not just weather
• Use a reference curve derived from sea trials, corrected for hull condition at the time

Building a performance function that works

1. Fix the reference. Without a defensible baseline speed–power curve, everything downstream is opinion.
2. Calibrate the meters. Annually, and cross-check continuously against soundings.
3. Automate ingestion. Manual re-keying of noon data into a performance tool reintroduces the error you are trying to remove.
4. Report weekly, not monthly. Fouling and operational waste compound; a monthly cycle loses three weeks of action.
5. Close the loop with the vessel. Performance data that never reaches the bridge and engine room changes nothing.
6. Link it to compliance. The same fuel data feeds MRV/DCS, CII, EU ETS and FuelEU. One number, one source, or the reconciliations begin.

Connectivity made this practical

High-frequency monitoring was historically limited by bandwidth. That constraint has largely lifted — LEO services moved shipboard connectivity from a scarce resource to a working utility, which is why "starlink maritime" appears in worldwide search data at all and why sensor-based performance programmes became viable across ordinary cargo fleets rather than just flagship tonnage.

What to do with the answer

Performance data is only worth what you do with it: