Global container schedule reliability fell 5.9 percentage points month-over-month in August 2026 to 49.9%, its lowest level since September 2022, according to issue 181 of Sea-Intelligence's Global Liner Performance (GLP) report.

It was the second consecutive month of sharp deterioration, driven by severe port congestion across Asia. Fewer than half of all vessels worldwide now arrive on time.

Delays are stretching out alongside the reliability slump. The average delay for late vessel arrivals increased 0.60 days month-over-month to 6.81 days — the highest figure since March 2022. Year-over-year, the August 2026 average delay was 1.92 days worse.

For shippers, the combination is doubly damaging: not only are more vessels missing their berthing windows, but the vessels that do arrive late are arriving later than at any point in more than four years. Forwarders managing inventory buffers and warehouse slot bookings face tightening planning windows, while BCOs with time-sensitive cargo will likely weigh premium products or alternative routings.

Carrier league table: Maersk leads, Wan Hai trails

Maersk was the most reliable of the top-13 carriers in August, with schedule reliability of 67.3%. Hapag-Lloyd followed at 61.5%. MSC and CMA CGM posted 55.2% and 50.6% respectively — the only two carriers in the 50–60% band.

Wan Hai was the least reliable carrier at 23.2%.

No carrier among the top 13 recorded a month-over-month improvement in August. ONE logged the smallest decline at -3.5 percentage points; PIL suffered the largest at -10.1 percentage points.

The year-over-year picture is equally bleak. None of the 13 carriers improved on August 2025 levels. Maersk again showed the most resilience with the smallest Y/Y decline of -8.9 percentage points. PIL posted the steepest fall at -31.1 percentage points and was one of twelve carriers with a double-digit Y/Y decline — underscoring how broadly the congestion shock has hit, rather than being confined to weaker operators.

Alliance breakdown: Gemini dominates

The alliance-level data shows a wide gap between network models. Gemini — the Maersk–Hapag-Lloyd partnership built around hub-and-spoke scheduling — was the most reliable alliance in July/August 2026 with schedule reliability of 77.8%, nearly 28 percentage points above the global average.

MSC, operating as a standalone network on the alliance tables, achieved 70.1%. Ocean Alliance managed 48.3%, while Premier Alliance was the least reliable grouping at 43.2%.

The spread between Gemini at 77.8% and Premier Alliance at 43.2% — a 34.6-point gap — gives shippers a concrete differentiator when negotiating service commitments. Carriers outside the Gemini and MSC networks face growing pressure to explain persistent slippage, and may need to lean on schedule recovery measures or port rotations that bypass the worst congestion points in Asia.

What comes next

With reliability falling for two straight months and late-arrival delays at a post-March-2022 high, the trajectory depends heavily on how quickly Asian port congestion clears. Until berth waiting times normalize, shippers should expect continued volatility in arrival windows — and carriers able to protect schedule integrity will keep commanding a premium.