Sailors of the naval, merchant or fishing fleets, and those who use the sea for sporting or recreational purposes, all share the same goals: to forsake the humdrum beaten track of mere mortals and venture forth, challenging the elements and testing themselves in a quest for the infinite and freedom. In the past it was a lack of appropriate land and especially air travel facilities that was a primary motive for this; now it has its roots in an over-regulated society, seen by some as oppressive and standardised. This craving for the open air is experienced every time one leaves port.

The men of the sea were some of the earliest, if not the first, to show an interest in space; it was ever present, throughout the long starlit watches of the night, and it offered the only navigational references that could guide them to a safe harbour.

The uniqueness of the oceans lies primarily in their vastness. The medium is relentlessly changeable and the vigilant mariner, be he sailor or strategist, has to be constantly alert to his environment and the need to master the art of ship handling. Over the centuries mankind has therefore made strenuous efforts to develop ever more advanced means of acquiring situational awareness, and positional and navigation information, and to facilitate the observation, communication and forecasting of weather, and hydrological and oceanographic phenomena.