Is Being Beside the Sea Beside the Point?

The first half of the Gospel of Mark talks about Jesus's travels in the northern part of Israel, in the region known as Galilee. However, he repeatedly mentions that Jesus is beside the sea and that he crossed the Sea of Galilee five times. Compared to Matthew and Luke, this is a notable thing that Mark does. So, why does he bring this up over and over again, especially when being by the sea is irrelevant to what is described in the Gospel reading? Mark is addressing an ancient conviction about the sea representing chaos and uncertainty, danger and fear, and makes the point that Jesus is unmoved by and unconcerned about it . . .