Core Bulk Trade

Marine Fuel and Bunkering Glossary

The terms used daily on bunker desks, in charter party negotiations and in supply disputes.

Fuels and grades

The grade determines price, compliance status and handling requirements.

  • VLSFO — very low sulphur fuel oil, maximum 0.50% sulphur, the global compliant default
  • ULSFO — ultra low sulphur fuel oil, maximum 0.10% sulphur, used inside emission control areas
  • HSFO — high sulphur fuel oil, typically 3.5% sulphur, for scrubber-fitted tonnage
  • MGO and MDO — marine gasoil and marine diesel oil, distillate grades
  • Bio-blends — conventional fuel blended with FAME or HVO, quoted as B24, B30 and similar

Commercial terms

These terms define who bears which risk in a bunker transaction.

  • Stem — a confirmed bunker order for a specified quantity, grade and window
  • BDN — bunker delivery note, the legal record of quantity, grade and sulphur content
  • Ex-wharf — delivery at a terminal berth rather than by barge
  • Ex-pipe — delivery by shore pipeline
  • Delivered by barge — the standard hub supply mode
  • Nomination — the buyer's notice of vessel, port and window to the supplier

Quality and disputes

Nearly all quality claims turn on sampling. The MARPOL sample taken at the receiving vessel's manifold is the reference sample in most jurisdictions and should be witnessed and sealed.

  • Cat fines — catalytic fines, abrasive particles measured as aluminium plus silicon
  • Stability reserve — a fuel's capacity to hold asphaltenes in suspension
  • Compatibility — whether two fuels can be commingled without precipitation
  • Off-spec claim — a formal claim that delivered fuel failed the agreed specification
  • Quantity dispute — a disagreement over delivered volume, usually resolved by joint survey

Equipment and compliance

Compliance choices determine which fuel a vessel can economically burn.

  • Scrubber (EGCS) — exhaust gas cleaning system enabling compliant HSFO use
  • ECA — emission control area with a 0.10% sulphur limit
  • Fuel changeover — the procedure for switching grades before entering an ECA
  • Debunkering — removing fuel from a vessel, typically after an off-spec delivery