For others, just a way to let loose.

But despite its casual association with fun and sun,

surfing has a richer and deeper history than many realize.

What we today call surfing originated in

the Polynesian islands of the Pacific Ocean.

We know from various accounts

that wave riding was done throughout the Polynesian Pacific,

as well as in West Africa and Peru.

But it was in the Hawaiian archipelago in particular

that surfing advanced the most,

was best documented,

and, unlike elsewhere in Polynesia, persisted.

And for the people of Hawaii,

wave sliding was not just a recreational activity,

but one with spiritual and social significance.

Like much of Hawaiian society,

nearly every aspect of surfing was governed by a code of rules and taboos

known as kapu.

Hawaiians made offerings when selecting a tree to carve,

prayed for waves with the help of a kahuna, or an expert priest,

and gave thanks after surviving a perilous wipeout.

Certain surf breaks were strickly reserved for the elite.

But it wasn't just a solemn affair.

Surfers competed and wagered on who could ride the farthest,

the fastest,

or catch the biggest wave with superior skill,

granting respect,

social status,

and romantic success.

Though it was later called the sport of kings,

Hawaiian men and women of all ages and social classes participated,

riding surfboards shaped from koa,

breadfruit,

or wiliwili trees.

Many Hawaiians road alaia boards,

which were thin, midsized, and somewhat resemble today's shortboards.

Some mounted paipo boards,

short, round-nosed boards on which riders typically lay on their stomachs.

But only chieftains could ride the massive olo boards,

twice as long as today's longboards.

Unlike most modern surfboards,

all boards were finless,

requiring surfers to drags their hands or feet to turn.

We don't know exactly when wave sliding was invented,

but we know that it had already been practiced in Polynesia for centuries

by the time it was described in 1777 by William Anderson,

a surgeon on Captain Cook's ship "Resolution."

Although Anderson was in awe,

most of the American Christian missionaries who arrived in Hawaii

several decades later

regarded surfing as sinful,

and they discouraged it, along with other aspects of native culture.

The biggest threat to surfing, however, was the threat to the natives themselves.

By 1890, new illnesses introduced by Europeans and Americans

had decimated the Hawaiian people, leaving fewer than 40,000

from a pre-contact population that may have exceeded 800,000.

At the same time, foreign influence grew

with white settlers overthrowing the native monarchy in 1893,

and the U.S. annexing the islands five years later.

The end of Hawaii's independence coincided with surfing's native-led revival,

a revival soon exploited by the American colonizers.

But first, some Hawaiians took surfing overseas.

In 1907, George Freeth, the so-called Hawaiian Wonder,

traveled to the west coast

and gave surfing demonstrations in southern California.

Then in 1914, Olympic swimmer Duke Kahanamoku

made his way to Australia and New Zealand,

gliding across the southern Pacific waves

and attracting rapt audiences wherever he went.

Shortly before Freeth went to California,

a South Carolinian named Alexander Hume Ford moved to Hawaii.

After learning to surf, he became a champion of the pastime.

But Ford may have had unsavory reasons

for his enthusiastic efforts to boost the sport.

Like many settlers, he wanted Hawaii to become a U.S. state

but was worried about its non-white majority of natives and Asian workers.

Ford thus promoted surfing to attract white Americans to Hawaii,

first as tourists, then as residents.

He was helped by numerous writers and filmmakers.

Ford's demographic plan would fail miserably.

Hawaii became a state in 1959

and remains the most racially diverse state in the country.

But the promotion of surfing was a far greater success.

Today, surfing is a multi-billion dollar global industry,

with tens of millions of enthusiasts worldwide.

And though relatively few of these surfers are aware of the once-crucial wave chants

or board carving rituals,

Hawaiians continue to preserve these traditions

nearly washed away by history's waves.