Glossary

Tracking

AIS — Automatic Identification System. A radio signal ships broadcast with their position, speed, course, and a crew-entered destination.

Terrestrial AIS — AIS received by shore-based stations. Dense near coasts; the right fit for the Baltic.

Satellite AIS — AIS received from orbit. Needed on the open ocean, not in coastal seas.

Port call — a vessel's arrival at and stay in a port. The unit VPM predicts.

Voyage — the passage between two port calls.

ETA — estimated time of arrival.

Geofence — a defined area around a port used to detect when a vessel has arrived.

Fuel and emissions

Bunkers / bunkering — marine fuel, and the act of delivering it to a ship.

Stem — a confirmed bunker order: the quantity and grade a vessel takes on.

MGO — marine gas oil. A clean distillate fuel, low sulphur.

VLSFO — very low sulphur fuel oil. A residual fuel blended to meet the 0.5% sulphur cap.

HFO / heavy fuel — heavy fuel oil. Cheap, high sulphur; compliant only with a scrubber.

LNG dual-fuel — an engine that runs mainly on liquefied natural gas with a small liquid pilot fuel.

Scrubber — exhaust gas cleaning equipment that lets a ship keep burning heavy fuel inside emission-control areas.

ECA / SECA — Emission Control Area / Sulphur Emission Control Area. Sea regions with a tighter sulphur limit; the Baltic and North Sea are among them.

CII — Carbon Intensity Indicator. An annual efficiency rating applied to each ship under IMO rules.

EU ETS — the EU Emissions Trading System, now extended to shipping: operators surrender allowances for CO₂ on EU-related voyages.

FuelEU Maritime — an EU rule setting a declining limit on the greenhouse-gas intensity of energy used by ships in EU waters.

MRV — Monitoring, Reporting and Verification: the formal emissions reporting regime.

Tank-to-wake — emissions counted from the fuel in the tank through to the ship's propulsion, excluding upstream production.

Cargo and vessel

Laden — carrying cargo.

Ballast — sailing without cargo, using water ballast for stability.

Ballast leg — a voyage sailed in ballast, typically to reposition for the next cargo.

Draught — how deep a vessel sits in the water. A loaded ship sits deeper; the difference indicates load state.

DWT — deadweight tonnage. The weight a vessel can carry, including cargo, fuel and stores.

GT — gross tonnage. A measure of a vessel's total enclosed volume, used for regulatory purposes.

Liner / tramp — a liner runs a fixed, repeating schedule; a tramp works the spot market with no fixed route.

Prediction and accuracy

Next port of call — the port a vessel will arrive at next. VPM's core prediction.

Top-1 / Top-3 — a Top-1 hit is when the single most likely predicted port is correct; a Top-3 hit is when the correct port is among the three most likely.

Back-test — replaying history to check what the model would have predicted, scored against what actually happened.

Hold-out — a portion of history kept aside from any tuning and used only for scoring, so the result is not fitted to itself.

Declared destination — the destination a vessel broadcasts over AIS. A strong signal when it is kept up to date, unreliable when it is not.

Confidence — how strong a given prediction is, shown per row so reliable calls read at a glance.

Roles

Husbandry agent — a port agent handling a vessel's local needs: pilotage, customs, provisions, waste, crew.

Charterer — the party that hires a vessel to move cargo.