The calming of the storm is a nature miracle.
Mark includes a lot of specific detail in the story which has led many scholars to believe that it is an eyewitness account. Mark notes that there were other boats on the lake.
Due to the location of Lake Galilee, it was common for storms to stir up quickly. The disciples - four of whom were experienced fishermen - would have been used to such occurrences. The storm must have been particularly dangerous if the disciples were frightened.
Mark notes that Jesus was asleep with his head on a pillow. Some scholars see this as symbolic as due to his trust in God as he was able to sleep peacefully with the storm raging.
The disciples woke Jesus as they were terrified for their lives. They display a lack of faith as they question Jesus, “Don’t you care that we are about to drown?”
Jesus stood up and commanded the wind and waves by simply saying, “Be quiet, be still.” As he did so there was complete calm.
The disciples were left in shock and awe at the end of the miracle and asked one another, “Who is this man? Even the wind and the waves obey him!”