Bono.

Bono, also known as the Seven Ghosts, is a legendary tidal bore that forms on the Kampar River in Sumatra when ocean tides from the Malacca Strait meet the river’s flow. The wave can reach heights of 4 to 6 meters and travel up to 60 kilometers inland, offering exceptionally long rides that can last over an hour. Surfers can experience both left and right waves on the muddy river water, which presents a unique challenge compared to ocean surfing. Hazards include strong currents, floating debris, crocodiles, and unpredictable local boat traffic, making safety boats highly recommended. The best time to surf Bono is during the strongest tides around full moon periods from October to December and February to March. The spot is typically uncrowded and embraced by the local community, which hosts annual surfing festivals. Access requires coordination with local boat operators and knowledge of tidal timings.

Ocean tide meets river flow sixty kilometres inland, where crocodiles share the muddy bore.