While ports of the world are more or less diversified, the influence of traffic diversity on the global port hierarchy and maritime network is not yet well understood. This research uses a complex network approach to analyze the interplay between no less than 20 shipping traffic types connecting more than 1,600 ports. A database covering about 155000 daily movements of 24000 vessels in 2008 is used to construct a global matrix of inter-port shipping flows. Main results show that the global network is highly dependent on more diversified nodes, which in turn catch the most traffic and exhibit higher connectivity. It also underlines the role and nature of specific shipping segments as layers of an all-encompassing maritime system.