I crept up on this one, being careful to save the white of the paper for the middle cluster of sails.

Watercolor Study of Sailboats

The sky began as a very flat wash.  I like it much better with the suggestion of clouds.  The organic shapes of the clouds balance the angular shapes of the sails and creates a sense of air and distance.  The pattern in the sky also allows for more color play in the water.

I used several layers of glazes for the water, the sky and the sails.  The sails of the boats on either side of the cluster of three have the look of off-white cotton canvas sails rather than the sharp white nylon sails that are on the center boats.  I played with the values of the cotton sails to create lost and found edges against the sky in order to avoid competition with the center sails.