Its Meaning
¥Jesus is asleep in the boat.
Is he tired?  Would not be surprising given his previous activity.
From the context, it appears that the point is that Jesus is asleep because he is trusting, in contrast to his disciples.
Note this interchange: Mark 4:38 (NIV) Jesus was in the stern, sleeping on a cushion. The disciples woke him and said to him, "Teacher, don't you care if we drown?" 39 He got up, rebuked the wind and said to the waves, "Quiet! Be still!" Then the wind died down and it was completely calm. 40 He said to his disciples, "Why are you so afraid? Do you still have no faith?"