I think this is a very sweet image. There is some nice balance to it with your two models and the emotive quality is very nice. I think the use of natural lighting was well handled and the focus looks pretty good. I don't get a strong sense of zen from the photo though, more a depiction of a zen-like action. I find the rolling waves in the background to contradict the stillness or serenity the actions of your models might be helping to create as well. I'm not sure how this looked in color, but the washed out nature of the waves is also a detraction for me, though I DO like the way it makes your models stand out. All told I gave a 5.
Although this photo has minimal color, there is alot of interest that draws the eye all over the photo... The movement of the two subjects, the movement of the waves, just makes it overall busy to the eye.