Beyond them is open sea and a flat horizon.

BBC: Sailing in Croatia

The only constants in this unfolding landscape are the route ahead and the horizon on a sea of eternal blue.

BBC: The perfect trip: Provence and the C?te d��Azur

With the Deepwater Horizon oil spill still saturating the sea weeks after the leak sprung, we also looked at an array of innovative solutions for cleaning up the catastrophe.

ENGADGET: Inhabitat's Week in Green: salad spinners, diapers, and solutions to the Deepwater catastrophe

One option being discussed is an over-the-horizon British rapid reaction force based at sea.

BBC: UK boosts Sierra Leone force

The sea offers space, a view to a distant horizon, a physical perspective less oppressive than hard-edged close-up urban architecture.

BBC: Alone at the seaside

Each morning, fleets of cobalt blue boats still head out from port, scattering across a vast Atlantic horizon - but now the daily haul is sea bass, not sugar.

BBC: Morocco��s best for coastal retreats: Essaouira

Then they dissolve into nothing, only to form as if by stealth on a different horizon, dancing across the sky in the shape of a sea horse or crescent moon.

BBC: The perfect trip: Norway

Stay until twilight when the horizon twinkles with the lights of container ships plying the busy South China Sea.

BBC: Vietnam's prison-island paradise