David Woodfall / Surfers & pleasure boats ride the bore, seen from the river. Severn Estuary. England

David Woodfall / Surfers on the bore. Severn Estuary. England

David Woodfall / Surfers on the bore. Severn Estuary. England

David Woodfall / Surfers on the bore. Severn Estuary. England

Steven David Miller / People and dogs on Tallebudgera Beach. Skyline of Surfers Paradise in background, Gold Coast, Queensland, Australia. 2016.

David Fleetham / Hawaiian monk seal (Monachus schauinslandi) hauled out on beach, with Green sea turtle (Chelonia mydas) and tourists and surfers in in the background Ho'okipa Beach off Maui, Hawaii.

Nick Upton / Three Eurasian spoonbills (Platalea leucorodia) resting on a small vegetated island in Sotavento lagoon with many kite surfers in the background, Fuerteventura, Canary Islands, May.

Nick Upton / Canary Island Raven (Corvus corax tingitanus) adult perched on sea cliff edge with surfers in the background, Fuerteventura, Canary Islands, May. This is the smallest subspecies of Raven, restricted t...

Nick Upton / Sotavento lagoon and kite surfers, near Jandia, Fuerteventura, Canary Isalnds, May.

Merryn Thomas / Surfer running on beach to sea, Rhossili, Gower, Wales. February 2013

Luis Quinta / Surfer riding a big wave, Nazare, Portugal, December 2015.

Luis Quinta / Surfer riding a big wave, Nazare, Portugal, December 2014.

Graham Eaton / Surfer entering the sea with large waves breaking over the jetty during an easterly gale, Criccieth, Gwynedd, North Wales, September 2013.

Graham Eaton / Surfer entering the sea with large waves breaking on the jetty during an easterly gale, at Criccieth, Gwynedd, North Wales, September 2013.

Cheryl-Samantha Owen / Crowd of people at Surfers Corner, Muizenberg Beach, False Bay, near Cape Town, Western Cape, South Africa. July.

Cheryl-Samantha Owen / Crowd of people at Surfers Corner, Muizenberg Beach, False Bay, near Cape Town, Western Cape, South Africa. July.

Cheryl-Samantha Owen / Crowd of people at Surfers Corner, Muizenberg Beach, False Bay, near Cape Town, Western Cape, South Africa. July.

Cheryl-Samantha Owen / Green flag emblazoned with the outline of a white shark means conditions, such as water visibility, the degree of wind, cloud cover or sun reflection on the waters surface, would allow surfers to spot...

Cheryl-Samantha Owen / Black flag with the outline of a white shark means conditions, such as water visibility, the degree of wind, cloud cover or sun reflection on the waters surface, would not allow surfers to spot any sh...

Cheryl-Samantha Owen / Surfer walking along beach, Muizenberg Beach, False Bay, near Cape Town, Western Cape, South Africa. July 2013.

Cheryl-Samantha Owen / Dennis Chikodze hoists the black flag at the Kalk Bay post. It provides a warning to ocean goers that visibility is bad and the shark spotters may not see a white shark if it does enter the bay. West...

Cheryl-Samantha Owen / Surfers on the waves at Surfers Corner, Muizenberg Beach, False Bay, near Cape Town, Western Cape, South Africa. June 2011.

Cheryl-Samantha Owen / Surfers stretching on beach, Surfers Corner, Muizenberg Beach, False Bay, near Cape Town, Western Cape, South Africa.

Cheryl-Samantha Owen / Surfer taking shower, holding board, Surfers Corner, Muizenberg Beach, False Bay, near Cape Town, Western Cape, South Africa. June 2011.

Cheryl-Samantha Owen / Young boy surfer with board, Surfers Corner, Muizenberg Beach, False Bay, near Cape Town, Western Cape, South Africa. June 2011.

Cheryl-Samantha Owen / Surfers walking to sea with board on beach, viewed through rain covered window, Surfers Corner, Muizenberg Beach, False Bay, near Cape Town, Western Cape, South Africa. June 2011.

Constantinos Petrinos / Windsurfer at Korfos Bay, Mykonos Island, Cyclades, Aegean Sea, Mediterranean, Greece, August 2007

Jean E. Roche / Kite surfing, Beauduc, Camargue, France, May 2014.

Jean E. Roche / Kite surfing, Beauduc, Camargue, France, May 2014.

Jean E. Roche / Kite surfing, Beauduc, Camargue, France, May 2014.

Jean E. Roche / Kite surfing, Beauduc, Camargue, France, May 2014.

Jean E. Roche / Kite surfing, Beauduc, Camargue, France, May 2014.

Jean E. Roche / Kite surfing, Beauduc, Camargue, France, May 2014.

Jean E. Roche / Kite surfing, Beauduc, Camargue, France, May 2014.

Jean E. Roche / Kite surfing, Beauduc, Camargue, France, May 2014.

Jean E. Roche / Kite surfing, Beauduc, Camargue, France, May 2014.

Jean E. Roche / Kite surfing, Beauduc, Camargue, France, May 2014.

Jean E. Roche / Kite surfing, Beauduc, Camargue, France, May 2014.

Jean E. Roche / Kite surfing, Beauduc, Camargue, France, May 2014.

Jean E. Roche / Kite surfing, Beauduc, Camargue, France, May 2014.

Onne van der Wal / Surfers off the coast of an Australian beach, New South Wales, November 2012.

Onne van der Wal / Surfers walking on beach, Australia. November 2012.

Onne van der Wal / Surfers at beach, New South Wales, Australia, November 2012.

Andy Rouse / Gentoo penguins (Pygoscelis papua) surfing onto beach, Carcass Island, Falkland Islands.

Kirkendall-Spring / Nate Harrison teaching his son Gabriel how to surf, Hobuck Beach, Makah Reservation, Washington, USA, August 2014. Model Released. Model released.

Rhonda Klevansky / Shadow of person with surfboard walking on beach, Durban, KwaZulu-Natal, South Africa, August, 2009.

Michael D. Kern / Surfers competing in the Mavericks 2014 surfing competition, with man on jet ski, Half Moon Bay, California, USA, January 2014.

Michael D. Kern / Surfers competing in the Mavericks 2014 surfing competition, watched by people on jet ski, Half Moon Bay, California, USA, January 2014.

Michael D. Kern / Harbour patrol boat and surfers competing in Mavericks Surfing Competition 2014, Half Moon Bay, California, USA, January.

Michael D. Kern / Surfer competing in the Mavericks 2014 surfing competition, watched by people on RIB, Half Moon Bay, California, USA, January 2014.

Michael D. Kern / Surfers competing in the Mavericks 2014 surfing competition, watched by people on jet ski, Half Moon Bay, California, USA, January 2014.

Michael D. Kern / Surfer competing in the Mavericks 2014 surfing competition, watched by people on jet skis, Half Moon Bay, California, USA, January 2014.

Michael D. Kern / Surfers competing in the Mavericks 2014 surfing competition, Half Moon Bay, California, USA, January 2014.

John Waters / Surfers walking to sea at Rhossili Bay, Gower Peninsula, Wales UK, September 2013.

Richard Du Toit / Aerial photograph of surfers on waves, Indian Ocean, KwaZulu-Natal Province, South Africa, May 2010

Merryn Thomas / Kite surfers on Bantham Bay, with Burgh Island in the distance. South Devon, UK. January 2009.

Merryn Thomas / Kite surfers on Bantham Bay under stormy skies, South Devon, UK. January 2009.

Benoit Stichelbaut / Three surfers chatting as they leave the water at the Festival de la Glisse, La Torche, Brittany, France. 1997.

Ross Hoddinott / Two surfers walking along the beach, Sandymouth bay, Cornwall, UK.

Alex Mustard / 2020VISION / Surfers carrying their surfboards down the beach, Fistral Beach, Newquay, Cornwall, UK, July 2011

Nick Upton / Alexanders (Smyrnium olusatrum) flowering on coastal cliff overlooking Hayle bay, with Pentire head and surfers in the background. Polzeath, Cornwall, UK, April

Nick Upton / Surfers heading out into the waves at Polzeath beach. Cornwall, UK, April 2010.

Nick Upton / RNLI surf lifeguards on duty at Polzeath beach, watching surfers in waves. Cornwall, UK, April 2010.

David Woodfall / Surfers & pleasure boats ride the bore, seen from the river. Severn Estuary. England

David Woodfall / Surfers & pleasure boats ride the bore, seen from the river. Severn Estuary. England

David Woodfall / Surfers & pleasure boats ride the bore, seen from the river. Severn Estuary. England

David Woodfall / Surfers & pleasure boats ride the bore, seen from the river. Severn Estuary. England

David Woodfall / Surfers & pleasure boats ride the bore, seen from the river. Severn Estuary. England

David Woodfall / Surfers ride the bore. Severn Estuary. England, August 2009

David Woodfall / Spectators line up to watch surfers on Severn bore. Severn Estuary. England, August 2009

David Woodfall / Surfers riding the Severn bore. Severn Estuary. England, August 2009

Nick Upton / Kite surfers riding waves near the shore at Rhossili Bay, The Gower Peninsula, Wales, August 2009

Nick Upton / Surfers in the sea at Polzeath. Cornwall, UK. Blue Flag Beach.

Nick Upton / Surfers and rock pools on Polzeath beach. Cornwall, UK. Blue Flag Beach.

Ross Hoddinott / Surfers walking along Sandymouth beach, Cornwall, UK

Onne van der Wal / Surfers and child on beach, South Africa. December 2008.

Fabio Liverani / Surfers wading through the shallows, Playa de Sotovento (Beach of Under Wind), Fuerteventura, Canary Isles, Spain, September 2007

Julia Bayne / Surfers Paradise beach New South Wales, Australia

Steven David Miller / Surfers Paradise coastline viewed from Q1 Building (highest residential building in the world) Gold Coast, Queensland, Australia.

Bob Barbour / Surfers at Mavericks, Half Moon Bay, California

Bob Barbour / Surfers riding breaking wave

David Fleetham / Helicopters filming tow-in surfers at Peahi (Jaws) off Maui, Hawaii.

David Fleetham / Tow-in surfers attempting to launch jetski at Maliko Gulch for surfing at Peahi (Jaws) off Maui, Hawaii.

Onne van der Wal / Surfers in wetsuits wading out through the surf into the cold waters of Middletown, Rhode Island, USA.

Barry Bland / Surfers in the water as a black storm cloud approaches St Clair Beach, Dunedin, New Zealand.

Merryn Thomas / Kite surfers on Bantham Bay, with Burgh Island in the distance. South Devon, UK, January 2009.

David Fleetham / Snorkelers and surfers entering the water off Hulopo'e Beach Park, with a resort over looking the golden beach and palm trees, with a lot of surf on the sand, Lanai Island, Hawaii, USA.