Republic of Kiribati
THE FAMOUS ARORAE NAVIGATION STONES
Arorae is the southernmost island in the Kiribati Group. It has an area of 9.5 square kilometres and a population of 1,527.
Shark-tooth sword of Arorae
THE FAMOUS ARORAE NAVIGATION STONES
These stones, or more correctly coral slabs, are located on the southernmost island in the Kiribati Group. They have been a source of wonderment to many people over the years with explanations that range between the logical and extremely fanciful.
The following explanation is from the notes of Captain Brett Hilder and they are, in my opinion, one of the more lucid explanations of this most fascinating phenomenon:
"When I went to Gilbert Islands in M.V. Tulagi in 1956, I was told of some coral stones on the island of Arorae which had been used for early canoe voyages. The natives called them "Te Atibu-ni-Borau" (the stones for voyages), but they had no legends about their origins or use.
They turned out to be flat slabs of coral erected on edge and paved around the base. They looked like grave stones, but had no inscriptions on them except recent initials in Roman letters. The stones pointed in almost all directions and were said to point the path to the various neighbouring islands of the southern Gilberts.
Arorae is about 5 miles long and barely a mile wide, pointing about south-east, into the trade wind. At the other end is a long spit of sand, which has been extended through the centuries because it is the lee end of the island. This is the site of the navigation stones which number eight or nine in all. There are a lot of other flat stones standing on the island, but they are boundary markers for plots of land and lines of coconuts.
As we reached the stones, we came to the first stone that was the largest of all and appeared to mark only the entrance to the navigation stone. The other eight stones pointed in five directions. Some of them were in pairs, side by side, while others were alone.
The site was about 100 yards from the beach from each side and about 200 yards from the tip of the island. Owing to the presence of various native huts and the vegetation of coconut palms and some bushes, it was impossible to see the sea from the stones. I couldnt see at this time how they could be used for navigating canoes across the open sea to other islands.
I plotted out the bearings on a chart and found that four of the directions pointed to the three nearest islands with a constant error of five degrees. Two of these courses were to windward of the their island goals, the other two were on either side of the nearest island, 52 miles distant.
It took me several months of research and deduction to determine a possible application of the navigational stones. We know that the native navigators used the stars by night to maintain a set course and two or three references turned up about the use of landmarks to set a canoe on its course in the late afternoon.
I finally came to the conclusion that the stones were used in the following way: when the directions to the nearby islands had been related to certain stars and each hour of the night at a given time of the year by trial and error over many years, some ingenious teacher hit upon the idea of setting up the stones as permanent sailing directions. They could have been used to check on the star's position and movement before the voyage was undertaken.
On the afternoon chosen for the departure, the canoe would be launched at the landing place, sail around to the tip of the island, and hove-to approximately in line with the correct stone or pair of stones. As these could hardly have been visible from a safe distance beyond the breakers, some temporary beacon must have been set up from the stones so they could be got in line, and placed right astern as the canoe made its departure. By the time the island was lost to sight, the stars would appear, and be used throughout the night. Most of the voyages from Arorae were a little more than 12 hours sailing, so at dawn, a masthead look-out would start scanning the horizon all round for the target island.
The five degrees error on each course may have been an intentional allowance for the set of the equatorial current, while the navigator would have to allow something also for the leeway due to the trade wind. This would vary with the course the strength of the wind and the trim of the canoe.
Arorae navigation stones
One of the stones pointed exactly northeast, in which direction there was no island for 1,000 miles. I finally assumed that this course was given, with the usual ceremonies, either to unwanted visitors or to people being exiled for crime against the community.
The stones, being so far from the sea, may have originally been on the tip of the island, but the extension of the island, during the centuries has now left them out of sight of the sea. There are several good reasons for this assumption, but these conclusions still left several parts of the puzzle unsolved. Mainly, how did these canoe navigators get back home again? The course they steered away from home included the five degree allowance for the current and, if they steered the opposite course, it would put them five degrees to leeward and they would be lost. These islands are really only coral reefs with low banks of sands on them, up to about 12 feet above sea level. The palms reach a height of about. 75 feet, so the islands are only visible from a canoe masthead at distances up to ten miles.
Arorae navigation stones
The method of navigation I have described would not be successful over 100 miles, unless their island goal was a long volcanic one, or a long chain of low islet. In navigation, it is not sufficient to steer a set course to reach a distant destination, as the set and strength of ocean current is very variable. So the position of the ship has to be fixed at intervals, or the latitude fixed at least, in order to reset the course as necessary to reach the destination. There is no evidence that the Micronesians could check their latitude and therefore we must assume that all their long voyages, up to 2,000 and 3,000 miles, were accidental or experimental, as Captain Cook was forced to conclude."