The pupils began with a line drawing using their work so far as a reference:

Having practised their drawing skills, they were able to used varied lines to suggest the movement and force of the wave:

Finally, it was time to start adding colour:

I encourage the pupils to discuss their work and to learn from each other as they work:

The final stage was to add definition using a thin black pen.

The finished versions look very effective on the KS2 board: