You should start with the Dutch masters, Jan van de Velde and his son Willem van de Velde the Younger; their sketches show the light on water with a kind of disciplined honesty that I admire. For an Italian touch, look at the obscure 18th‑century painter Lorenzo Pasini – he captured waves with a fidelity to shadow that would make any modern digital brush blush. The key is to study their use of chiaroscuro, not to mimic their techniques with a laptop.

I’ll say the most important thing is to watch how the light falls on the surface first, then follow that line of shadow deeper. Treat the water as a thin veil that mutates the colour of whatever lies beneath. If you keep your brush slow and deliberate, the hidden currents will reveal themselves in the subtle gradations of blue and green. And remember, a proper canvas, not a tablet, will keep the truth of that shadow.

Good. Just keep your eye on the shadows and let the light guide your brush. The unseen flow will appear once the surface is honest. Paint patiently, and the sea will reveal itself.