Gulf of Tonkin, Vietnam

This scene is an original illustration set in Gulf of Tonkin, Vietnam. It lies in the tropics, where the climate is monsoon-influenced humid subtropical — dry winters.

Sheer limestone towers rise straight from calm sea, each undercut with a distinct notch at the waterline. A floating farm of planks on blue barrels sits among them with a small hut on it. Thin morning haze softens the further towers into flat pale layers.

Why is there a notch cut around every limestone tower?

The notch is cut by seawater dissolving limestone in the narrow band that is constantly wetted — a precise record of sea level, and it runs at the same height on every tower. The towers themselves are the remains of a drowned karst landscape whose valleys filled when sea level rose. Floating aquaculture works here because the water is sheltered and deep right up to the rock.

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