Etymo

During the colonial days, British steamers regularly plied between London and various far flung out posts of the Empire. Journeys on these steamers took anywhere from a week to 3 months. Due to prevailing tides and wind conditions on the high seas, passengers preferred a cabin on the port side of a ship, when heading out of Britain, and the starboard when heading home. Hence passengers who could afford it paid higher fares for these cabins. Hence the rich and moneyed were able to secure the best cabins on a voyage for themselves. This has given rise to a term which is usually associated with the rich and fashionable.What is it?