Water as a subject has a contemplative nature which is very close to what I want a painting to be.
Paintings start with flat space.
I am working with this space rather than against it. In a similar manner because I work with water based acrylic paints for layering and masking, the obvious subject is the one closest to the material. When I'm working out how to paint a body of water it helps a lot to think of it as a set of layers. Normally there's some evidence of what the earth or sand under the water is like- its colour and shape. Next the water itself will have a range of colours - the deeper it is the more colour it has.