Congestion at Singapore's container port is at its worst since the COVID-19 pandemic, a sign of how prolonged vessel rerouting to avoid attacks in the Red Sea has disrupted global ocean shipping — with bottlenecks also appearing in other Asian and European ports.

Retailers, manufacturers and other industries that rely on massive box ships are again battling surging rates, port backups and shortages of empty containers, even as many consumer-oriented firms look to build inventories heading into the peak year-end shopping season.

Global port congestion has reached an 18-month high, with 60% of ships waiting at anchor located in Asia, maritime data firm Linerlytica said this month.