Shipping consultancy Drewry has warned that being "good at shipping" may not be enough if giant boxship lines succeed in diversifying throughout the whole supply chain.

It identified three strategies that owners have been taking to differentiate themselves from the competition: global integration in logistics, consolidating the core sea product or enhancing scale through fleet expansion.

Drewry said it has often been hard to distinguish one carrier from another "with few observable unique selling points aside from obvious regional affiliations and size."