Most bunker quantity disputes aren’t settled by anyone re-measuring the fuel. They’re settled by whoever kept better records at the time of delivery — and by then, the fuel is long burned.
The independent surveyor’s job starts before the hose connects: opening and closing soundings on the barge’s tanks, cross-checked against the barge’s own figures, with temperature correction applied consistently on both sides. A dispute six weeks later almost always traces back to one of two things — a sounding taken before the barge had settled from its last cargo movement, or a temperature correction applied with the wrong table.
Density and temperature at the time of transfer matter more than most receiving engineers assume, because bunker quantity is contracted by mass, not volume, and the conversion between the two is where small errors compound into real ones. A 0.5°C difference in recorded temperature, multiplied across several hundred tonnes, is not a rounding error — it’s a number a P&I club will ask about.
The paperwork that protects a vessel isn’t generated after a dispute starts. It’s the sounding log, the density certificate, and the surveyor’s report, all timestamped and consistent, sitting in the file before the barge has even cast off.