Originally Published: 16 AUG 22 10:04 ET

Updated: 16 AUG 22 13:09 ET

By Sara Ashley O'Brien, CNN Business

(CNN) -- Chris, a homeowner in Des Moines, was surprised when a woman he didn't know recently pulled into his driveway and asked if he could move his vehicles. She believed she had booked his pool for the night after someone had wrongfully listed it on a platform devoted to renting out private swimming pools. Within minutes of her showing up, he said, a few other cars arrived.

That was how Chris learned about Swimply, a relatively new service that has often been dubbed the Airbnb of swimming pools. "I said, 'Sorry, I'm not renting my pool out,'" said Chris, who asked to withhold his last name for privacy reasons. He said he was able to find the page on Swimply and within an hour, it appeared to be taken down.

Swimply described the situation to CNN Business as "incredibly rare." The company said there were "no red flags" when the account was created but when it became aware of the situation, it issued refunds, blocked payment to the host and removed the host and listing from its platform.

But Chris remains flabbergasted that such a service even exists. "Why anyone would rent their pool out like that to me is asinine," he said. "The amount of liability, I would never ever do it."

Founded in 2018, Swimply gained traction during the pandemic as many sought safe ways to travel and socialize outdoors with friends and family. Hosts, who set their own rates and give a 15% cut to Swimply, were able to bring in extra income at a time that was financially challenging for many. And Swimply, which moved its headquarters from the East Coast to Los Angeles, benefited.

The startup raised $50 million over two rounds in 2021, with buy-in from tech executives from well-known companies such as Airbnb, Instacart and Poshmark. It now has listings in more than 125 markets in the United States, Canada and Australia, and hit a key milestone of putting 1 million "butts in pools" to date.

In many ways, Swimply is emblematic of the next generation of on-demand platforms. Airbnb and Uber convinced strangers to get comfortable with renting each other's homes and hopping into each other's cars. Now, a newer crop of services offers the promise of helping people supplement their livelihoods by renting out anything and everything, from their garages and parking spots to backyards and swimming pools.

But just as earlier sharing economy startups have clashed with regulators over their business models -- not to mention a host of safety concerns -- Swimply has also already ruffled communities from California to Florida. And while it has created opportunities for hosts, it has also created a new set of uncertainties, from logistical issues around where to place an outdoor toilet to thornier questions around liability.

The company's cofounders are open about the challenges. Bunim Laskin, Swimply's CEO, said his startup operates in an "even greyer" area than Airbnb as it seeks to get people to fundamentally change how they view ownership and access. The company, he said, isn't just focused on private pools; it has recently begun expanding with other recreational offerings by allowing people to list any private amenities on their property, including tennis courts. (Known as Swimply Spaces, guests can sign up to be notified once the company formally launches the broader amenity listings later this year.)

"Everything is a double-edged sword," said Asher Weinberger, cofounder and COO of Swimply. "The sharing economy has done so much for the world and for people. On the other hand, there is an underbelly of that. There's a dark side of that, like everything in life, right?"

While many people may be more comfortable using Swimply because of the decade-worth of similar services that came before it, Weinberger noted that each company in the sharing economy needs to be managed, regulated and understood for what it offers.

As with some of its older peers, the way Swimply is understood and regulated could shift depending on the context in which people hear about it, and if there are enough high-profile incidents of rentals gone wrong.

In late June, a seven-year-old girl drowned at a pool in Teaneck, New Jersey, an incident that came amid a series of drownings in the area unrelated to Swimply, according to local news reports. Teaneck's Chief of Police, Glenn O'Reilly, confirmed to CNN Business that police responded to the incident, which resulted in the young girl being pronounced dead. In an email with the information issued at the time, O'Reilly said it appeared the pool was rented through Swimply and that there was a party taking place.

"It was a matter of when -- not if," Laskin said, of what he called the first drowning incident at a Swimply-reserved pool. (Swimply, for its part, has a partnership with a nonprofit called Colin's Hope to provide water safety resources and education to hosts and guests.)

"We investigated the situation to see where the fault was — could we have prevented it?" said Laskin, who noted the host was what's considered a "superhost," or someone who had achieved certain milestones such as having at least 100 bookings per year and a rating of 4.8 stars or above.

Even one such incident is "tragic," he said. But Laskin distinguished it as a "pool incident" rather than a "Swimply incident." As he put it, "the pool can be incredibly safe — but swimming is inherently something that requires supervision, discipline."

Making a splash

Like Airbnb and Uber, Swimply was borne out of a personal pain point for its founders.

Weinberger, who previously founded the menswear company Twillory, had recently moved into a new pool-equipped home on Long Island and his family members constantly wanted to come over for a dip. He'd been mulling over an idea of creating a scheduling service that would help people like him keep track of when people were slated to come over -- and, importantly, would provide insurance coverage for those guests while they're there.

The son of a rabbi, Weinberger had attended rabbinical school while also studying business administration in Israel. "I always want to keep one foot in both worlds," he said of his career thus far. In 2018, the same year he moved into his new home, he hosted a startup pitch competition for Orthodox Jews when he came across Laskin.

The oldest of 12 children, Laskin was home from Israel for the summer and attended to pitch his idea of building a platform for residential pool rentals by the hour. While helping care for his siblings, Laskin had been offering a neighbor money in exchange for occasional pool access. This soon spiraled into him becoming a sort of "pool broker" for other families as well, he said.

The two have since been working to bring Swimply to the masses. In March 2020, they made a television pitch on ABC's "Shark Tank," but it did not result in a deal. After the pandemic was declared that same month, the two fought to keep their startup afloat in an uncertain time.

"We were on our respective couches, in isolation, mutually depressed, asking each other, 'What do we do with this last $10,000?'" said Weinberger, of the company's remaining bank account balance. "We ultimately decided we're going to take a Hail Mary pass."

The pair assumed they could find a PR firm with "reduced rates" due to Covid-19. After looking around, they signed with a firm for two months, at a rate of $5,000 a month, effectively committing all their remaining money.

"We decided to give it a shot, maybe it will catch on. And it did, we caught fire," he said. "We were in the right place at the right time."

New opportunities and unknowns for hosts

Alexandra Watkins calls herself "a natural worrier." After having a negative experience as a host on a home rental platform, she said it took her a year to warm up to the idea of listing her pool on Swimply.

"I really vacillated back and forth," said Watkins, who recently registered as a Swimply host in San Diego. To get comfortable with the idea, she looked for tips from more veteran hosts online, consulted her insurance provider and had a waiver drawn up for guests. She also created her own set of rules for renters and said she plans to prohibit anyone under the age of 18 and the consumption of alcohol entirely.

"I'm trying to reduce our liability as much as possible," said Watkins. She also wants to prevent being a "jerk neighbor." Her listing, which touts her tropical tiki bar, a fence lined with surfboards, and pink lounge chairs, warns possible guests: "This is our home, not a Vegas hotel."

In 2021, Swimply introduced an insurance policy that protects "all bookings via Swimply for up to $1 million for general liability claims," an offering that Weinberger said the company knew from the start would be key to its value proposition of keeping people safe. He called it a "huge, huge win" to be able to offer it -- but questions remain about whether it is enough to cover what could arise and whether any potential claims fall within the platform's lengthy terms of service agreement. (Swimply said it has not yet needed to issue a payout to any users through the liability insurance program.) It also offers up to $10,000 of property protection per incident, a program through which some hosts have received reimbursements over minor damages, the company said.

Michael Duff, a professor at Saint Louis University School of Law, cautioned that what a company sets forth in an agreement is not the law, and shouldn't be taken as such.

"It's never the law. It's somebody's idea of the way things would work. Even if you've signed a contract that says, 'I understand I'm waiving my right to judicial relief.' Some states honor that, and there are other states in which you cannot waive negligence that easily," Duff said. "You would literally have to go state by state to figure out: Is it really this easy to waive liability?"

Legal and insurance experts said hosts should at minimum contact their homeowner insurance provider about renting out their pools for private use. Swimply's terms of service also recommend this, and make clear that the onus is on hosts to comply with any applicable laws or licensing requirements.

"When it works -- it works great. But when it doesn't, you have this really high downside," St. John's University law professor Miriam Cherry told CNN Business, referring to sharing economy companies that connect strangers for a service.

On its end, Swimply said it reviews every pool on the platform in an attempt to weed out fake or unsafe listings and runs background checks. It also requires that hosts be home when reservations include 15 guests or more. Hosts are expected to notify their neighbors of their rentals, and follow any neighborhood rules such as pertaining to parking. Discrimination of any kind is prohibited, and Swimply also has a rule banning sexual activity, including "undressing with the intent of sexual gratification, so please plan your day accordingly," according to its website.

Hosts are encouraged to add their own rules, too.

"My rules are very simple: No drinking inside the pool, no smoking, no taking any plants from the property," said Armando Gonzalez, a host in Moreno Valley, California, told CNN Business. He said he also requires guests bring their own lifeguard or have an adult supervise when there are more than 10 children (his capacity is 100).

So far, Gonzalez said the only issue he's really had in his more than 40 times hosting is with the plants. "For some reason, they tend to take some of my plants," he said, noting that one pricey succulent of his was snagged by a guest. "I think I paid about $200 for that plant. I just have to take the loss. There's nothing I can do."

CNN Business spoke to two hosts who happened to work in the insurance industry as their primary job but who began renting out their homes on Swimply to make extra income. They've each rented a porta potty for guests to use to avoid having people traipsing through their homes.

One of the hosts, Sonia Perez of San Antonio, Texas, said the issue of liability was initially her "biggest concern." Perez, who started using Swimply this summer, said she's always home and has only had an issue once, with some rowdy young adults who left trash behind.

The other, Marcia Clarke, lives in Atlanta and has been hosting on Swimply for the past two years. Clarke said the costliest expense she's incurred so far is a broken $400 pool ladder, which she didn't learn about until after the guests left. She ate the cost, she said, and implemented a new policy of doing a full walkthrough with guests at the end of their reservation.

"How is it any different than me hosting a party and charging guests?" said Clarke. And the extra income, Clarke said, has been a "huge, huge help financially."

Fabiola Farrah Colas-Williams and Kyle Williams have also found Swimply to be useful to help support the cost of pool maintenance, given their family, which includes two teenagers, doesn't use it often. They started using Swimply earlier this summer for their property in Suffolk County, New York, and are now thinking about other home amenities they can list, including their home movie theater.

Before they list an amenity inside rather than outside their home, however, "we have to have a plan for the kids, for what we're going to do [if it is rented out]," Fabiola said. "So we haven't really decided when we're going to make that listing live."

Communities see an opportunity to wade in early

Over the years, Airbnb forced cities to grapple with an influx of short-term rentals and the various impacts such transient stays had on their communities. Some passed laws to make it illegal to rent out places for short stays, or fewer than 30 days, for example.

Now, after a decade of battling Airbnb, some communities are moving quickly to respond to Swimply.

Palm Springs determined Swimply to be prohibited in areas zoned for single family homes under its zoning code, which does not allow for commercial use, according to a report from the Desert Sun, which city official Veronica Goedhart confirmed to CNN Business.

"Across the board, Swimply pools are not open to the general public and therefore are not commercial property," Swimply told CNN Business. "We believe Swimply is in current legal standing in the community and listings should not be prohibited in the area. However, we are looking forward to working with the City shortly to better define their regulations for those wishing to list or book a pool via Swimply."

Meanwhile, in the Pinecrest suburb of Miami, councilmember Anna Hochkammer led a charge to insert new language into the community's code that prohibits residents from renting "residential property for recreational use."

"Swimply is really just the most recent iteration of what's been a constant headache for cities throughout Florida," Hochkammer told CNN Business, referring to the evolution of the vacation rental economy spurred by Airbnb. In 2011, the Florida legislature preempted local governments from being able to prohibit companies like Airbnb, she said. "We've had to go back time and time and time again to tweak our code to the extent possible to be able to bring some sort of accountability to these businesses."

As they expanded, Uber and Airbnb each hired lobbyists to help pass favorable laws that would help support their business practices. Asked whether Swimply had already hired lobbyists, Laskin said: "We have a team. ... It's a brand new team that we put up this year now that we're getting traction or are being recognized."

"We have to get proactive," he added.

Right now, he said, the company is often thought of as a platform for people to have pool parties, which might sound to some like it could devolve into a raucous blowout. But he claimed 95% of pool reservations are booked for parties of fewer than five people and noted that all the listings are primary residences where people live. "The experience is meaningfully intimate, beautiful, and generally replicating what the owner would use the pool for," Laskin said.

However, the pool party use case is an image Swimply promotes through its own marketing. During the course of reporting this story, this reporter was served multiple Instagram ads for Swimply. One read: "Swimply presents: The Pool Party." It featured three adults jumping into a pool with inflatable tubes around their waists.