The main objective of the breakwater systems is to protect the closed water yard from waves and
storms, as they help bring calm inside the port and thus achieve safety for ships inside it, and ease of operation.
This paper presents the results of the study on wave interaction with vertical slotted water breakers. The research
was conducted on two breakwater models, each of which was defined as follows: The first breakwater has two
perforated walls: the lower portion is porous, while the top part is solid, while the second wall is the polar opposite
of the first, with a porosity of 50% in both. The second breakwater is similar to the first, but it lacks the horizontal
slit wall. The first and second breakwaters were compared, and the result indicate that the first breakwater
hydrodynamic output performance the second in the range (10-15 %).The second breakwater is affected by the
wave force less in the range (85-90%) than its breaker first counterpart. On the models that have been tested, the
wave's force increases as its relative length (h/L) increases. According to the results of this study, the transmission
factor (kt) rises as the relative length (h / L) decreases, while the reflection factor (kr) decreases as the relative
length (h / L) reduces. FLOW-3D has the ability to calculate the velocities in front and behind the breakwaters and
can be used in similar studies.