Bunker surcharges faced by ships should be lower than the current amounts paid, according to Drewry.

The shipping consultants stated that surcharges should have declined faster than fuel charges. It argues this is because ships have become more fuel efficient and cheap fuel is now available in Russian ports.

It states ships become more efficient as size increases. On a return route between Asia and north Europe, 18,000 twenty-foot equivalent unit (teu) vessels burn around 35 per cent less fuel per teu than 13,100 teu alternatives.

An increase in larger ships means more fuel cost efficiency. The average ship between Asia and north Europe in the third quarter of 2011 was 9,158 teu in capacity, increasing to 9,881 teu in a year and in excess of 10,800 teu by two years.

A spokesperson for Drewry concluded: "This means that bunker surcharge levels should have been falling faster than fuel prices since [the third quarter of 2012], which is not immediately apparent [from results]".