The shipping industry has long been regarded as one of the more reliable indicators of global economic health. But quite how reliable depends on which shipping barometer is followed. As measured by the Baltic Dry Index, the daily benchmark for shipping rates of bulk goods, the world would seem to be mired in another grim downturn: since February, it has been languishing at its lowest levels for two years. Fortunately, this slump in the BDI is less a proxy for worldwide demand in raw materials, which remains resolutely high, and more a sign of overcapacity in the worldwide bulk fleet. Th ere is such a surfeit of newly built cargo ships to transport all that coal, grain and iron ore to China that the carrying costs of those commodities has simply plunged.

Container ships, on the other hand, have just come off an unexpectedly bumper year. Denmark’s AP Møller- Maersk, operator of the world’s largest container fleet and several oil tankers, has just announced a record net profit of DKr28.2bn (€3.8bn) for 2010, a year after announcing the only full-year loss in its 107-year history. Singapore’s Neptune Orient Lines and Korea’s Hanjin Shipping have also reported financial rebounds.

Th is reflects more than just a dramatic recovery in manufactured and semi-finished goods. Container prices also shot up last year because Maersk and its competitors couldn’t reactivate laid-up ships fast enough to meet demand. Such was the spike that there ended up being a shortage in standard-sized ‘20ft’ containers – a dearth that may persist a year or two as box-makers reboot their own idled plants.

While Maersk chief executive Nils Andersen forecasts a “softening”, he still expects global trade to grow by 6%-8% in 2011. Backing up that optimism, Maersk has just placed “the greatest shipyard order ever”. Ten of the world’s largest container ships will be built for it by South Korea’s Daewoo Shipbuilding, with an option on 20 more. Since these can anchor at only a handful of ports (including Hong Kong, Port Said, Felixstowe, Rotterdam, Bremerhaven and Shanghai – there are none in the US), that amounts to a $6bn (€4.3bn) bet on growth in the Asia-Europe routes. Once operational in 2013, they will use 50% less fuel per container than the current average – a commitment that will also boost Maersk’s bottom line given the soaring price of oil.