Tidal bulges are formed during high tides, when the gravitational pull of the moon causes the surface of the ocean to rise on both the side of the earth facing the moon, and its direct opposite. There are always two lunar tidal bulges on Earth. (http://www.scienceclarified.com/Ti-Vi/Tides.html)
High tides are formed when the moon pulls the surface of the ocean upward. Low tides are formed when that gravitational pull is lessened and the water sinks. Because of the moon's and Earth's orbit, the tides are both a daily occurrence, and a seasonal one. During Spring Tides and "Neap" Tides, there are especially high and low tides around the planet. (https://www.qldscienceteachers.com/junior-science/astronomy/tides-eclipses-day-night-seasons)