Singapore-based bank DBS (Singapore Exchange: DBSM-SG) is hoping an aquatic event can help it ride the millennial wave.

The bank is marketing directly to that generation — often defined as those aged 18 to 35 — for a regatta this Thursday to Sunday in downtown Singapore . What began as a dragon boating event in 2013 is now firmly geared toward millennials, featuring the country's largest inflatable obstacle course, a 21,000 square foot "pop-up" urban beach, yoga workout sessions and a mass drone light display show.

The youngest adult generation is a particularly desirable clientele because it is projected to make up 45 percent of the Asia Pacific population by 2020, according to Accenture.

Millennials will therefore form the bank's largest costumer base in the coming years and banks such as DBS are paying close attention to the spending patterns and trends within the segment. In fact, that generation's habits could even put banks out of business: The Millennial Disruption Index from Viacom Media identified banking as at the "highest risk of disruption."

That report found 33 percent of millennials interviewed said they wouldn't need a bank at all: With the rise of digital payment systems, many are turning away from the traditional brick-and-mortar banks.

Such findings have caused banks to rethink their marketing strategies.

"[Millennials] value experiences, they like to travel, they are digitally savvy, so we believe that if we can embed ourselves, we can be part of their lives," Sim S. Lim, DBS Bank's Singapore country head, told CNBC's "Squawk Box" on Friday.

The annual event was first introduced by the bank as a way to revitalize Singapore's Marina Bay waterfront promenade.

But it has morphed into a full experiential pitch to millennials.

Understanding that segment prefers to spend on experiences rather than luxury goods, the bank has partnered with electronic dance music organizer Ultra Singapore, sportswear brand Lululemon (LULU) and Bali's Potato Head Beach Club.

"This is why our regatta this year specifically focuses on themes that are close to [millennials'] hearts — fitness, wellness, music and entertainment," said Karen Ngui, DBS Bank's head of group strategic marketing and communications .

Targeting different segments within the millennial consumer space is important, according to Ang Swee Hoon, associate professor of marketing at National University of Singapore Business School.

"Not all millennials are the same. They may belong to the same age group but there may be differences in attitude and lifestyle," she told CNBC.