And just as the 13-month ILWU talks and accompanying labour action prompted shippers to shift some discretionary cargo away from the West Coast, the upcoming contract negotiations for the International Longshoremen's Association (ILA) could have a similar effect with freight looking to avoid East and Gulf coast ports.

Another potential factor benefitting the West Coast is the ongoing draft and width restrictions implemented along the Panama Canal due to an ongoing drought. Mr Cox said the limits were marginally reducing the effective capacity of container lines from Asia calling US East and Gulf coast ports. The restrictions will be in place through June at the least, according to New York's Journal of Commerce.

Also, retail customers in general have worked through their elevated inventories, Mr Cox said, boding well for restocking through importing. E-commerce demand growth helped offset an otherwise weak peak season ahead of the holiday shopping season, with Matson's volumes from China to the US down 1.3 per cent in the third quarter compared with a year ago, according to the carrier.

Meanwhile, major ocean carriers are reducing effective capacity, said Mr Cox, referring to the more frequent blank sailings and skipping of port calls that are coming with less warning and pulling scheduled reliability down further.