• Fishing and cycling are among the ultra-rich's top ten favorite ways to spend their time, according to new research by wealth intelligence firm New World Wealth and investment migration consultancy Henley & Partners.
• Watch collecting is also a new addition to the list since 2000, pushing wine collecting out of the top ten.
• For some of the ultra-rich, this means spending as much as $1 million on a single watch.

Spending time on yachts, golf courses and the slopes of exclusive ski resorts might be what first comes to mind when thinking about how the ultra-rich like to spend their time.

And while those are all in the top ten pastimes of so-called centi-millionaires — anyone who has assets worth over $100 million – other activities on the list might be more surprising.

Fishing and cycling are among the ultra-rich's top ten favorite ways to spend their time, according to new research by wealth intelligence firm New World Wealth and investment migration consultancy Henley & Partners.

Cycling and mountain biking beat skiing to third place, with only golf and art collecting being more popular. Horse riding rounds out the top 5, followed by fishing in sixth place — ahead of classic car collecting, hunting, yachting and watch collecting.

It might be hard to imagine the same people who spend their time buying vintage cars priced as high as $40 million (for a Ferrari 250 GTO from the 1960s) standing in a river waiting for fish to bite or hurtling down mountain biking trails, but the activities have soared in popularity.

Back in 2000, both cycling and fishing were much lower on the list, ranking seventh and tenth respectively, New World Wealth told CNBC's Make It.

Among anglers, fly fishing was especially popular. Fly fishers' favorite rivers are scattered around the world, from the U.S. and Scotland to New Zealand, but tropical holiday destinations are also gaining fans, according to the report.

"Ocean fly-fishing is also rising in popularity. Top spots for this include Australia, the Caribbean, the Mozambique Channel, the Seychelles, and the South Pacific," it said.

Watch collecting is also a new addition to the list since 2000, pushing wine collecting out of the top ten. For some of the ultra-rich, this means spending as much as $1 million on a single watch, such as those by luxury brand Patek Philippe, Henley & Partners says in an article accompanying the report on their website.

Who are centi-millionaires and where do they live?

These individuals "are typically the founders of successful companies or the CEOs of large multinational organizations," the report said.

"Many centi-millionaires have their own private jets and super-yachts. Their assets and finances are normally managed by private family offices, and they traditionally have three or more homes that they move between throughout the year," it added.

The report registered 25,490 centi-millionaires globally as of June 2022, with close to 9,700, or 38%, of them living in the U.S., where five of the top 10 wealthiest cities in the world are located. China, India, the U.K., and Germany round out the top five.

The population of this group of ultra-rich people is soaring, the report says.

"Their numbers have more than doubled over the past 20 years," it explains. The biggest centi-millionaire boom is set to take place in emerging regions like India, where their numbers are expected to surge by up to 80% in the coming decade.

"At around 57%, the growth of centi-millionaires in Asia will be twice that of Europe and the USA over the next 10-year period," Henley & Partners wrote on their website.