When large tides travel many kilometers over shallow water the front of the tidal wave, that is, the first part of the flood tide, steepens. It may form a "bore," which is a traveling form of hydraulic jump. The Hooghy estuary in India and that of the Tsien Tang in China have the biggest bores. Other large bores occur in the Amazon, Seine and Severn. The Severn bore is seen here in a turbulent condition crossing water that is about 20 cm deep over Rodley Sands opposite Framilode.

D.H. Peregrine died peacefully with his family around him in Southmead Hospital, Bristol on 20th March 2007.

This photograph was taken from "An Album of Fluid Motion," by Van Dyke, Parabolic Press. This book is available at a bargain price of about $25. It might make a nice present for someone.