Rectangular submerged vertical breakwater (RSVB) is a barrier with its crest below the still
water level. For economical solution of submerged rectangular vertical breakwater, I have to make
some holes in it to be permeable with different permeability ratios (p) to use as wave energy
absorption for the defence of the shore line. So in this paper experiments were done in the wave
flume in the laboratory of Hydraulics, Civil Engineering Department, Shorouk Academy, Higher
Institute of Engineering. This is under normal and regular waves with different ranges of wave
heights and periods under different water depths. The efficiency of the break water is presented as a
function of the transmission, the reflection and the wave energy loss coefficients. A permeable
(RSVB) with constant width (W) = 50 cm as the total width of the experimental flume and different
heights (Y) worked one by one or with each other’s (stepped) with different water depths (dw),
different wave heights (Hi) and some holes with diameter φ = 4.0 and 2.0 cm acting from one to
fourth rows, with different heights (S) from base. Comparing the percentage of energy reduction
calculated between this type and impermeable (RSVB), working as single or as a group (stepped) as
shown in figure (1).