The number of people taking part in open water swimming in the UK has increased rapidly in the last decade, with the number of regular swimmers fast approaching 100,000.

What used to be a pastime for a handful of people up until the early 2000s, the latest figures from the Active People Survey (APS) show that 93,500 people now swim in open water every week. The growth seems to be accelerating too, as the APS figures for 2009 showed that less than 50,000 were regularly swimming outdoors.

The growth is seen to be largely down to the emergence of commercial operators and the increasing number of open water races and events – many of which cater for all abilities, lowering the barrier for people to jump into a lake or the sea.

As well as those chasing an adrenaline rush, outdoor swimming is also luring existing swimmers looking for “something different” – often after growing bored of their regular swimming pool experience.

According to open water swimming advocate and founder of H2Open, Simon Griffiths, swimming in a lake or the sea offers many attributes that indoor pools and leisure centres lack.

“Open water swimming is exciting, adventurous, sociable and challenging,” Griffiths said.

“The sport – or rather, activity – really does offer something for everyone. For the competitive, there are mass participation races; for the adventurous, there are long distance challenges and swimming tours; for endorphin junkies, there’s cold water swimming; and, for the sociable, there are now clubs and groups that meet around the country to swim, eat cake and chat.

“In addition, some of the tracking and route sharing technology used in cycling and running also works brilliantly in open water.”

Another factor aiding open water swimming’s popularity is the shifting attitudes towards outdoor spaces.

In an increasingly urban society, many are finding a new appreciation to nature and open space and are increasingly pursuing activities in a more “green” environment.

A report – commissioned by the Department for Culture, Media and Sport (DCMS) – published last month showed that nearly 90 per cent of people value outdoor spaces, such as the coast, lakes and waterways, as much as they value leisure centres, pitches and courts for sport.

The report also found that eight in ten people believe that ministers should support outdoor recreation in the same way as it supports sport – while 83 per cent agree that schools should give every child the chance to take part in outdoor recreation such as sailing, climbing and orienteering.

• The most recent APS figures – published last week – show swimming remains the UK’s most popular participation sport with just over 2.5 million people regularly taking to the water, but numbers have been falling steadily in recent years.