Your examiner asks: "What is the difference between EEDI and SEEMP, and which applies to your ship?"

A. The Energy Efficiency Design Index (EEDI) is a one-off, design-stage calculation of CO2 emissions per unit of transport work, mandatory for new ships of qualifying types/sizes and verified at the newbuild stage (existing ships instead use the EEXI, calculated retrospectively); the Ship Energy Efficiency Management Plan (SEEMP) is an operational, ship-specific management plan (covering speed optimisation, hull/propeller maintenance, voyage planning, etc.) required on board all ships of 400 GT+ regardless of EEDI/EEXI applicability, and is a living document reviewed and updated periodically.

B. EEDI and SEEMP are two names for the same single document, used interchangeably.

C. SEEMP is a design-stage calculation; EEDI is the operational management plan — the definitions are the reverse of common usage.

D. Only passenger ships require either an EEDI or a SEEMP; cargo ships are exempt from both.

A. An Emission Control Area (ECA) is a designated sea area (e.g. Baltic Sea, North Sea, North American coasts, Caribbean) with stricter SOx (and in some, NOx Tier III) limits than the global rule. The global sulphur cap is 0.50% m/m (since 1 January 2020, IMO 2020); inside a SOx ECA the limit is stricter, commonly cited at 0.10% m/m, requiring either low-sulphur fuel, approved equivalent means (e.g. an exhaust gas cleaning/scrubber system), or use of an alternative fuel meeting the limit.

B. ECAs apply only to NOx and have no relationship to fuel sulphur content at all.

C. The global sulphur cap and the ECA sulphur cap are numerically identical; ECAs only add extra reporting paperwork.

D. ECA status applies only to passenger vessels; cargo ships transiting the same waters are exempt from the ECA sulphur limit.

A. A documented changeover procedure must be followed before ECA entry, completed in good time so that all fuel oil systems are flushed of higher-sulphur fuel before entry; the date, time, position and fuel oil tank quantities at the time of changeover (both entry and exit) must be logged — this changeover log is a specific item PSC and class auditors check, and is also entered in/cross-referenced with the Oil Record Book.

B. Fuel changeover may be completed instantaneously at the ECA boundary with no advance flushing of fuel lines required.

C. Only the changeover into the ECA needs to be logged; the changeover back to higher-sulphur fuel on exit has no logging requirement.

D. Fuel changeover logging is a class society recommendation only, with no regulatory basis under Annex VI.