Sri Aman Tidal Bore

A tidal bore forms where a large tidal range meets a river with a shallowing funnel-shaped mouth, and the incoming tide, unable to spread, piles into a wave that travels upstream against the current. The Batang Lupar at Sri Aman produces one - the benak - which runs up the river at spring tides around the new and full moon, largest around the equinoxes, as a wall of water a metre or more high moving at some speed with a following surge. It is announced in the local tide tables and people gather on the esplanade to watch it pass. The town holds a Pesta Benak festival built around it, and surfers and kayakers ride it, as they do the Severn bore and the Amazon pororoca. Boats are moved out of the way beforehand. Sri Aman was formerly Simanggang and the Fort Alice of 1864 stands in the town.

What you actually see

• A wave running upriver - the benak travelling against the current at spring tides.
• Tide-table timing - the arrival announced and the town gathering to watch.
• Surfers and kayakers - riding it as on the Severn and the Amazon.
• Fort Alice - the 1864 fort in the town above the river.

When to go

Around new and full moon; largest at the equinoxes. A day.

Honest expectations

The bore runs only on the right tides - check the tide table before travelling or there will be nothing to see. Size varies a great deal between events. Do not go onto the riverbank or into the water when it is due.

Nearby

Batang Ai and the longhouses are inland; Kuching is west.