Jeremy Coles
The tricks and twists of surfers amaze us, but below the surface lies a raft of surfing science as impressive as the feats performed on the waves.
From highly skilled professional athletes to hobbyists after the rush of the open waves, surfing is enjoyed by people from all walks of life, from all over the planet. While the tricks and twists of seasoned professionals amaze us, below the surface lies a raft of surfing science as impressive as
the feats performed on the waves.

How are waves formed
The ocean is never still. Waves are created by energy passing through water, causing it to move in a circular motion. However, water does not actually travel in waves. Waves transmit energy, not water, across the ocean and if not obstructed by anything, they have the potential to travel across an entire ocean basin.
Waves are most commonly caused by wind. Wind-driven waves, or surface waves, are created by the friction between wind and surface water. As wind blows across the surface of the ocean or a lake, the continual disturbance creates a wave crest. These types of waves are found globally across the open ocean and along the coast. As long as the wave travels forward slower than the speed of the wind, energy will be transferred from the wind to the wave.
In fact, it is this wind power that may prove to be one of the most promising sources for renewable energy; potentially supplying 10% of global needs. The equations that can accurately determine the amount of energy in a wave are complicated. In general, the bigger the wave, the more the power and there are few places on Earth where the waves are as big as they are at Nazare in Portugal.
These monster Portuguese waves can reach epic proportions of over 30m thanks to a combination of the location of the coast and the unique undersea features. Waves generated by storms in the North Atlantic are focused by a deep, arrow-shaped canyon 4877m below the ocean's surface; these deep water waves then approach the shallow waters of the shore and start to climb up, meaning the waves at Nazare can get big. Real big!
"To surf waves at Nazare is an honour. You sort of feel like you're back in the day of the gladiators when the world is watching and you're trying to survive and perform at the same time," says Jamie Mitchell, World Surf League Big Wave Tour surfer.
Aside from Nazare, there are a few other ‘big wave’ spots around the world where the perfect conditions come together to create the kind of waves that surfers dream of. Teahupo`o village on the south-west coast of Tahiti is one such place. The waves here are big and steep and with the very real threat of falling onto its razor-sharp reef it has attracted the world’s best and bravest (perhaps craziest) surfers.

Ocean animals inspiring surf technology
A most classic part of a surfboard are its fins. Earlier surfboards were plain, and fins were introduced in the 1930s. Traditionally, fins were rigid and made of wood, but advances in plastics and composite materials have produced fins that allow for greater control while turning on a wave. These fins are on the underside of a surfboard. Fins are critical to the stability, feel and control of the board.
A new era has been reached when inspiration for fins has come from Nature. Whales are huge creatures, but very graceful. Their fins help them keep balance and achieve sharp turns. They have four fins, one tail fin for propulsion, two pectoral or arm fins that serve as rudders and stabilizers. The dorsal fin has some peculiar features but often is missing. Their flippers not only help them stay so nimble, they allow them to perform some impressive underwater acrobatics, especially in their tight, controlled turns.
Recent surf fins have been made that mimic whale flippers. This new type of fin bends or flexes starting from the stiff edge at the front, to the rear edge in such a way that there is more flexibility at the back. The fin also tapers from front to back, which is important since it is the front edge (also called leading edge) which first makes contact with the water. This creates more speed in the turn as the flexing fin snaps back into place.
A second, more radical, fin design has a bumpy irregular surface along the leading edge. It is modelled after the tubercles on a humpback whale’s flipper (see photo). As water flows over their flippers the large bumps create channels of fast-moving water which let the whale ‘grip’ the water at sharper angles, tightly turning and circling, even at slow speed. This improves its aerodynamics and in fact this has inspired the twisted shape of the blades of wind turbines as well.

More inspiration
It can be cold on the waves, even in relatively warm places, because of the wind and the water. Surfers need to stay warm so that their muscles do not cramp and they can respond quickly if a sudden large wave strikes. So surfers usually wear wetsuits. Engineers from MIT in the United States studied the fur of beavers and sea otters which live in wet cold places. These semi-aquatic mammals have remarkable fur that traps pockets of air to keep them warm and dry when diving
under water.
The MIT team fabricated furlike rubbery pelts mimicking this unique ability to help them understand and ultimately recreate the effect. The wetsuit is still in the design stage.

Surfboards to monitor our oceans
Scientists know that the world’s oceans are changing; they are getting warmer and more acidic, leading to rising sea levels, stormier weather, and altered ecosystems and animal behaviour.
To measure our changing oceans and the effects on ocean life, scientists use research vessels, probes, sensors and satellites to collect a range of data from the open ocean, but it is much trickier nearer the shore where the waters can be rougher and much more challenging.
All this may be about to change thanks to a neat piece of technology designed by a team of scientists and used by citizen science surfers. Smartfin is a new technology almost identical to a traditional surf board fin, but with a hidden twist. The fin contains sensors that measure temperature and location for researchers to analyse. In the future, Smartfin hopes its sensors will be able to measure pH, salinity, dissolved oxygen and levels of chlorophyll.

Dolphins like to surf
Dolphins have been observed riding the crest of big waves towards the shore and heading back out to sea before it breaks; even going out of their way to repeatedly ride the bow waves of large ships and whales, often leaping into the air with what seems like enjoyment.
So why would dolphins expend energy and waste time for what looks like little benefit? One theory is that they are playing - the behaviour looks to us like fun, it is done intentionally and voluntarily, and is repeated. Importantly, it is not performed when the animal is threatened or competing.
Equally it could also be that using the power of the waves is a more energy efficient way of travelling than swimming underwater. The impact of entering the waves might help to dislodge parasites on the skin, or the splashing noise it makes could also be a signal or communication to other dolphins in the area. There may also be free food when done alongside a fishing vessel, and when done in groups it may teach social bonding.
The answer could be a combination of any or all these; however, we like to think that perhaps dolphins just love to surf as much as we do!
Surfing is popular in lots of western countries and is getting popular in India as well. Now we see that the science of surfing is equally popular among scientists!

Main source: BBC Earth, http://www.bbc.com