Night Fishing: Analogous colours & Impressionist technique

This is an analogous painting exercise for my Impressionist painting class. Working from a black and white photo,  the aim is to work with a limited palette of analogous colours and create the gradations of light to dark.  The logic behind the palette is to choose the darkest colour and the lightest colour using colours that are in the same family.  In this case I was using ultramarine blue, phthalo blue and phthalo green.  The sttongest highlight was a cadmium yellow for the moon and water reflections.
The images below show the progression of the painting.  This first stage of the painting was created with just ultramarine blue.  When the paint was dry, I mixed a palette of analogous colours (see on the bottom).

The drawing is kept very simple.  Small individual brush strokes are used to loosely indicate the major shapes of light and dark.

I continue to build up the surface with the different tones of ultramarine blue.  I let the paint dry and then go on to recover the surface with the analogous colours.

I start with the sky, using the phthalo green mix for the moon and then progressively lay in the the relatively darker colours in the sky then in the water.

Once the whole surface is equally covered with the blues and blue greens, I finally add the pale cadmium yellow in the moon and water.

Analogous colour palette:

Here is a close-up of the surface showing the individual brush strokes and the texture created by superimposing the paint: