Clever idea for this source! Author, before I make a suggestion, I should say that shadows are a problem area for me. I noticed the shadows from the palm trees aren't going in the same direction as the light source. Look at the boat, if the light were coming from behind, as your palm trees indicate, there would be some sort of shadow going in front of the boat. I see the light source coming from the left, not behind. Hope this makes sense and good luck

Thanks Christy, took your advice, now there's no question that the light source is high and to the left.