The US Coast Guard says shipowners notched up another year of strong compliance with port state controls. But the industry appears to be slightly worsening in terms of pollution and fire fighting measures.

The 2017 Port State Control annual report noted that "compliance with international conventions and the safety of shipping has increased dramatically in the last two decades."

As evidence, the report showed the annual detention ratio of ships calling on the US was just under 1% last year, the lowest level recorded, compared to a 1.09%