6' 4", but whats a few inches between friends. Expression of slight nervousness as the owner of the boat approaches with a look of imminent hostilties on his phizog.
I hope that your latest statement does not mean that I was incorrect about confidence. It would be a blow to my image of 6' 2" Englishmen (got it right this time!) to realize that the expression here expressed is one of nervousness about the chance of falling out of the boat.
Further analysis brought to mind the visual metaphor present here: the firm grip on the motor's handle represents the man's firm grasp on the dangers posed to mankind and the resolve needed to deal with them.