The report, which covers schedule reliability across 34 different trades lanes and more than 60 carriers, shows that schedule reliability is not getting worse, but not getting better.

In July 2021, schedule reliability dropped by 3.8 percentage points month to month to 35.6 per cent. On a year-on-year level, schedule reliability was down 39.7 percentage points.

"The average delay for late vessel arrivals continued to deteriorate in July 2021, increasing by a further 0.35 days month on month to 6.88 days. The level of delays in 2021 has been the highest across each month compared to previous years," said Alan Murphy, CEO of Sea-Intelligence.

Maersk Line was the most reliable top-14 carrier in July 2021, with schedule reliability of 47.3 per cent. Hamburg Sud, a Maersk unit, was the only other carrier with schedule reliability higher than 40 per cent, with only four carriers between 30 per cent and 40 per cent, six between 20 per cent and 30 per cent, and the remaining two under 20 per cent.

Evergreen had the lowest schedule reliability in July 2021 of 16.2 per cent. None of the carriers recorded a month on month improvement in July 2021. The largest month-to-month decrease was of 9.6 percentage points recorded by Zim. None of the top-14 carriers recorded a year-on-year improvement in schedule reliability, with all carriers recording double-digit declines of over 32.0 percentage points.