This was just a quick little demo on painting transparency. In this painting the background was painted first and allowed to dry. Then the water, then the boat again they were allowed to dry. When I painted the sail etc. I painted quickly and with few strokes and a big brush so as not to disturb the paint underneath. If you take too many strokes it will become muddy.
This is from a series of fire paintings I've been doing lately because I live in Southern California and in my county we've experienced a hellish fire season. Beautiful to paint though using a basic red, yellow and blue palette. If you really want to learn watercolor, paint fire and sky's as they really do paint themselves.