Initially the island was placed on the starboard side because early propeller aircraft turned to the left more easily because of torque. Once the starboard side position was established it became difficult to change. Pilots used to landing with the island to their right would be confused on a ship with the island on the other side, there was nothing to be gained by changing the location, so it stayed in the same place.
There were, however, two carriers with their islands to port. The Japanese Akagi and Hiryu were fitted with port-side islands. Each was meant to work in a tactical formation with a starboard-island ship (Kaga and Soryu respectively); it was thought that putting the islands opposite sides would improve the flight patterns around the carriers, with aircraft marshalling in opposite directions in the circuit. The carriers with islands on the starboard would travel on the portside of the formation and their aircraft would circle to port. Those with islands on the port travelled on the starboard and their air groups circled to starboard. Wartime experience showed it to be an unnecessary complication with no advantages. The idea was scrapped after the first two ships of the class, the remaining 2, and all later carriers, having starboard islands.
Last edited by ORAC; 22nd Apr 2006 at 15:09.