For study of the speed with which the changes in sea level may occur in the Western harbor of Alexandria intervals of one hour and one day are selected for the height differences in sea level. From these sets of observations the general characteristics of the rate of sea level variations have been obtained. The results indicated a marked difference between the calm summer and autumn months on one hand and the stormy winter and spring months on the other hand. The daily sea level variations indicate an average sea level rise. Almost 85% of these variations occur within the limit of 5 cm. The largest value does not exceed 20 cm. The positive day-to-day changes are used for the determination of the renewal time of the water in the harbor basin, which is expected to occur in a period covering slightly more than 2 years. The average amount of water involved every year in the renewal is determined at 0.035 km3.