The Rajang River Delta is subject to daily, diurnal (twice per day) tides that are some of the world’s highest amplitude. These are classified as macrotidal in the southwestern distributary channels of the Rajang, Belawai, Palau and Lassa rivers, and mesotidal towards the northeastern Igan distributary channel. Macrotidal regimes experience a vertical displacement of water greater than 4 meters, whereas mesotidal regimes experience a rise-and-fall of tidal waters between 2 and 4 meters. In the case of the Rajang and Belawai rivers, King Tides (highest of high tides) can attain nearly 6 meters of displacement every 12 hours, several times each year. Prior to the internet and instantaneous data, books of yearly tidal cycles were published by the Malaysian government to assist in navigation of Sarawak rivers. Needless to say, the timing and extent of daily tides controlled logistics and sample recovery in channels.
The indigenous peoples of Sarwak are ethnographically complex. In the Rajang Delta, the main ethnic group are the Iban (Sea Dayak) and Melanau (in-and-around Bintulu in the southwest). Both groups are former head hunters, now converted to Catholicism, and live in raised, stilted long houses adjacent to the river. Access to each lodging is via a stilted landing, generally tin covered and, in general, built higher than the highest tide, with wooden planks connecting it to the longhouse.
High (King) and low (Neap) tides expose the channel margins to unusual conditions, and require a degree of sophisticated engineering to maintain boat houses, board walks, and floating docks that are subjected to wide swings in position over the macrotidal to mesotidal range.
By the early 1990s, lights and “essential” modernization had arrived in several longhouses where electricity was provided via petrol generators. It was possible at night to hear the two-cycle-stroke generators and see low-wattage lights in the longhouses from anchorage in the channels. But, other modern comforts were not seen, although these were there in longhouses that had attained a bit more wealth. This was apparent in mid-October, 1992, when we arrived at this particular boat landing along the Igan River to negotiate for laborers. Here, we found written in permanent marker on the inside of the corrugated tin roof, “Miss Alabama,” a beauty queen who must have made a very strong impression on someone here. How ironic to have flown more than 16,000 km (>8500 miles) from Atlanta, Georgia, USA, to Kuching, Sarawak, East Malaysia, for a project funded to, and administered by, Auburn University, Auburn, Alabama, and encounter “Miss Alabama” in an Iban longhouse. The world suddenly became a much smaller America. It became a much smaller universe.