Mark Hamblin / 2020VISION / Fallen Silver birch leaves (Betula sylvestris) and foam swirling in river eddy, Glen Affric, Highland, Scotland, UK, February

Graham Eaton / An underwater view of a mountain stream showing internal reflections on the water surface, Snowdonia NP, Gwynedd, Wales, UK, December 2009.

Graham Eaton / Potholes in carboniferous limestone beds, created by small pebbles in eddy currents eroding rock when River Ure is in spate, Lower Aysgarth Falls, Leyburn, Yorkshire, England, UK, October 2016.

Yva Momatiuk & John Eastcott / Sockeye Salmon (Oncorhynchus nerka) group resting in eddy during spawning run, Adams River, Roderick Haig-Brown Provincial Park, British Columbia, Canada

Benjamin Olson / Northern White Cedar (Thuja occidentalis) needles spinning in eddy at base of waterfall near Grand Marais, Minnesota, multiple exposures

Duncan Usher / River eddy at night in winter, Weser River, Lower Saxony, Germany

Onne van der Wal / Model boat builder, Robert Eddy, working on the mast of a scale model of the 1915 Herreshoff schooner "Mariette" in his shop in Camden, Maine, USA.

Onne van der Wal / Model boat builder, Robert Eddy, adding detail to a scale model of the 1915 Herreshoff schooner "Mariette" in his shop in Camden, Maine, USA.

Onne van der Wal / Model boat builder, Robert Eddy, with a scale model of the 1915 Herreshoff schooner "Mariette" in his shop in Camden, Maine, USA.

Onne van der Wal / Scale model of the classic 1915 Herreshoff Schooner "Mariette", made by Robert Eddy, Camden, Maine, USA.

Onne van der Wal / Model boat builder, Robert Eddy, working on the bow section of a scale model of the 1915 Herreshoff schooner "Mariette" in his shop in Camden, Maine, USA.

Onne van der Wal / Bow section of a scale model of the classic 1915 Herreshoff Schooner "Mariette", made by Robert Eddy, Camden, Maine, USA.