Austronesian and Arab Navigators

Navigators used a succession of rising and setting stars associated with their destination to steer the vessels. Their concept of the star dome and the world ocean was a stationary vessel and a moving destination island and nearby islands during the voyage. This is in stark contrast to the system developed and slowly refined by the Europeans in the latter half of the 2^nd Millennium AD which centred around a chart of the globe with defined latitude and longitude lines and a vessel moving across the globe from one location to another defined by coordinates; the vessel moved across the globe towards a stationary destination.

SE Asia, Micronesia and Polynesia the destinations of a community were many and varied and navigators would have many star combinations to commit to memory. To remember the stars the navigators had a complex memory system and floor/ground illustrations as teaching aids. The people who could grasp the system became revered and were held in high esteem to the extent that a system of priesthood developed and the knowledge was passed on to a chosen few. In the region of Austronesia 3000 years ago the navigators developed a star compass as a mind concept and used circular diagrams and since they were without a written language small objects indicated star positions.

A star compass of Mau Pialug illustrating the use of shells to indicate star positions

The star compass is also called a sidereal compass to indicate it is based on the star time and not sun time that is about 4 minutes more every day difference. The Earth rotates once in about 24 hours with respect to the sun and once every 23 hours 56 minutes and 4 seconds with respect to the stars.

The Caroline sidereal compass, the cross marks the astronomical centre (after Goodenough, 1953)

The navigation star compass perfected in the Caroline Islands was very similar to one developed by the Arabian sailors. 

An Arab star compass of the 19^th Century (after Tibbetts 1971)

The migration of the Austronesians across the Pacific from the Philippine and Indonesian territory started around BC 1000 in a general southeast route across Melanesia. This preceded written language and the influence of the Greeks, Arab and Indians when trading opportunities arose. The migration headed northeast to the eastern Caroline Islands in BC 200 and then headed west to the western Caroline Islands.

Migration from the western Indonesian Islands westwards across the Indian Ocean started around 500 AD. In the Maldives islands south of India the Austronesians met the Arabs and they might have found that their independently evolved star compasses were very similar. 

The Arab and Indians had a written language so the stars were named on the diagram record. The Arabs generally had a more north-south navigation routes and were less dependant of E-W rising and setting stars. But crucially the Arab and Indians were able to determine time and that allowed longitude sailing.

This shows the independent development of a star navigation system by two cultures separated for thousands of years.