The idea
Look down into clear, shallow water on a sunny day and the seabed ripples with bright, shifting lines of light. Those patterns are called caustics — sunlight bent by the moving surface of the water, focused into ribbons of brightness below. In this lesson, that piece of physics becomes a painting: a representational sea scene with a starfish resting on the sunlit bottom.
What you’ll learn
- How to build a sea painting from scratch — and which materials to choose
- How to create the light flecks of the sea using plain water — a displacement technique where clean water pushes pigment aside, leaving light behind
- How to make the starfish look dimensional and submerged using reflected color
- How to paint the entire picture with only three watercolor paints
The three-paint constraint
Limiting the palette to three paints isn’t a restriction — it’s the lesson. Mixing every sea green and sand gold from three pigments teaches more about color than a full paint box ever could, and it guarantees the finished painting holds together harmoniously.
How the session flows
The painting builds in layers: the sketch, the sea laid in wet washes, the sunlit flecks lifted out with water while everything is still damp, and finally the starfish — shaped, shaded, and settled into its reflections until it sits convincingly under the water rather than on top of the paper.
An enrichment lesson from Ayesa Kaur’s studio library, adaptable from young painters through adults.