Mark 6:47-50 - He was about to pass them by

6:47,48

The crossing wasn’t easy, as Jesus saw the “disciples straining at the oars”. However, there is no indication that they were in danger, just that it was hard work. Just before dawn Jesus went out to them walking on the water. The fact that it was just before dawn meant that they would be able to see Him, albeit dimly. “He was about to pass them”.  Schnabel suggests that “passing” here is actually being used in the sense of God passing by Moses (Ex 33:19), and is used in this sense elsewhere in the Old Testament, i.e. the disciples would encounter the divinity of Jesus.

6:49,50

The disciples did see Jesus, but thought He was a ghost. There are two contributory factors to this. One is that it was just before dawn, so while there would be some light, it would not be good light. The second is that they did not expect to see anyone walking on the water! They cried out in terror. On hearing them Jesus said “Take courage! It is I. Don’t be afraid”.