What factor seems to
influence how high or low the tides will be?

the gravitational forces exerted on the earth by the moon, and to a lesser extent, the sun. When the highest point in the wave, or the crest, reaches a coast, the coast experiences a high tide. When the lowest point, or the trough, reaches a coast, the coast experiences a low tide.

the most common type of reef is the fringing reef. this type of reef grows seaward directly from the shore. they form borders along the shoreline and surrounding islands.