Having loaded coal from Gladstone, Australia, towards the end of January, a capesize bulker embarked on a seemly ordinary journey to China.

The Australia-China trade lane is one of the busiest in the world, with hundreds of coal shipments taking place each year. If things go smoothly, such journeys can be completed within three weeks.

Yet somehow, the 176,200-dwt Roberto Rizzo (built 2009) had to stay at the anchorage of Rizhao for 10 days after arriving there in mid-February.