Global Air and Sea Routes
A world map showing commercial shipping routes (in green) and air traffic (in blue).
The ships - obviously - avoid land masses, with the two notable exceptions of the Panama Canal and the Suez Canal which each offer significant short cuts.
The major producer and consumer regions of North America, Europe and East Asia are heavily served.
The curvature of the longer routes is mostly a consequence of the mapping of the spherical earth using a conventional map projection. The air routes map has some "high arcs" near the top, indicating some trans polar routes which are less viable to shipping because of the arctic ice.
Presumably air and sea navigators may still modify routes to accommodate the prevailing winds and currents, and so save time and fuel costs.
Sea [Shipping] data source:
Air data source [Kevin Reinhardt]:
See also the splendid NATS video: