Depth limited design wave heights in very flat regions

Engineers working on the flat tops of offshore coral reefs or offshore banks, require design criteria for depth limited wave heights over horizontal beds, particularly in regions leeward of the bank or reef edge surf zone. This paper presents convincing evidence of the fact that in engineering practice, both in the laboratory and in the field, the value of 0.55 is the largest wave height to water depth ratio realizable for stable, shallow water oscillatory waves propagating in water of constant depth (horizontal bed). This value is much lower than that often used in engineering practice, namely a value of about 0.8, which is historically based on the theoretical considerations and laboratory experiments associated with solitary waves. This result, based on a review of laboratory data and the original results of a major field experiment undertaken on the Great Barrier Reef of Australia, leads to a significant reduction in design wave forces, design crest levels and wave induced scour velocities at the bed.