JMNT(i)
48 And seeing them being continuously tested (having the touchstone applied; being distressed; or, as a middle: = exerting themselves) within the midst of the constant driving [of the storm] and the need to be continuously rowing – for the wind continued being hostile and contrary, blowing in the opposite direction against them – He proceeded to come towards them, at about [the] fourth watch of the night (between three and six A.M.), progressively walking along upon the sea (or: lake). Now He had been intending to go past them (or: to pass them by; to go by alongside of them),
49 yet those having seen Him continuously walking around upon the sea (or: lake) suppose that it is the effect of an apparition (or: presume that He is a phantom or a ghost; thought that it is the result of something being made visible) and they cry out loud (or: let out a shriek) because they all saw Him and were shaken (troubled; disturbed; unsettled; agitated).
50 So He immediately speaks (or: spoke) with them, and continues saying to them, "Take courage, and continue being bold and confident! I am (or: I am Being; I am continuous Existence; or: = It is I)! Stop being afraid (or: Do not continue to be fearful)."
51 Then He stepped up toward them and climbed into the boat – and the wind at once subsided (grew weary and abated; suffered exhaustion and flagged). At this, within and among themselves, they became extremely astounded [other MSS add: from the extraordinary situation] and continued, as it were, standing outside themselves in amazement and kept on marveling with admiration.