Laboratory observations of green water overtopping a fixed deck

A small-scale laboratory experiment was conducted to quantify a transient wave overtopping a horizontal, deck fixed above the free surface. Detailed free surface and velocity measurements were made for two cases with and without the deck structure to quantify the effect of the deck on the wave kinematics. The study showed that the structure increased the free surface above the leading edge of the deck by 20%. The velocity profile at the leading edge was fairly uniform, and the maximum horizontal velocity was similar to the maximum crest velocity measured without the deck. Immediately below the deck, the maximum velocity was 2.5 times greater than the corresponding velocity without the deck and 2.1 times greater than the maximum crest velocity without the deck. On the deck, the wave collapsed into a thin bore with velocities that exceeded 2.4 times the maximum crest velocity measured without the deck. (C) 2002 Published by Elsevier Science Ltd.