A proposal from leading shipowner associations is calling for the of carrying non-compliant heavy fuel oil onboard ships to be “prohibited” after 2020, whether it is being used or not.

The motion aims to prevent owners from burning high sulphur fuel on the high seas but switching to low sulphur fuel oil when a vessel is at port or near shore and available for inspection by port state control (PSC).

Under Marpol Annex VI from 2020 the global limit on the sulphur content of fuel will be reduced from the current 3.5% to 0.5%.

The shipowner associations -- which include Bimco, the International Chamber of Shipping (ICS), Intertanko, Cruise Lines International Association (CLIA) and International Parcel Tankers Association (IPTA) -- are concerned that some operators may seek to gain a significant financial advantage by breaking the rules and burning cheaper low sulphur fuels when away from the coast.

The submission has been made to the International Maritime Organisation (IMO) group discussing the implementation of the Marpol Annex VI regulation which will meet in February next year.

“The implementation of the 0.5% sulphur limit in trades away from the major shipping lanes is also a major concern, especially if there is a tightening of the supply of compliant fuel oils and a significant fuel oil price hike in 2020,” the joint submission said.

However, the submission also outlined some exceptions where the carriage of non-compliant fuel with a sulphur content above 0.5% should be permitted.

These include when the fuel is being carried as a cargo, when the vessel is deploying a scrubber to remove the sulphur from exhaust fumes or when the ship has been granted an exception.

Ships which have filled out a fuel non availability report - known as a FONAR - detailing how they were unable to secure non-compliant fuel could be granted an exemption by PSC.

The industry submission is also suggesting that there should be some room for error incorporated into the testing procedures for compliant fuel.

The proposal said that test results from analysis of 0.5% fuel demonstrate that testing is not 100% accurate and it is recommending a 95% “confidence factor” is introduced to allow for “marginal non-compliances.”

“The co-sponsors believe that such marginal non compliances will steadily decrease during the transitional period and that they should be recognised as different from wilful non-compliance,” the groups said.