If you’re looking for some serious return on investment, owning a boat isn’t a great idea. Not only are there storage and maintenance fees to pay every year, but a boat typically isn’t used all too often — especially in a place like Seattle, where the sun doesn’t shine as much.

That problem is exactly why Aaron Hall started Boatbound two years ago. And so far, it appears he’s come up with a pretty good fix.

The San Francisco-based startup is like Airbnb, but for boat rentals. Its premise is simple: Owners put their boats up on the Boatbound marketplace; interested renters pay to use the boats for either a half day or full day.

Both the buyer and seller benefit — an owner makes money when his property would otherwise sit idle, and renters get to enjoy a day on the water without having to purchase a boat.

“Whether you are looking to take your family out on the water, hold a meeting on a yacht, impress a girl with a creative date, waterski, or lazily canoe down a river, Boatbound makes that possible,” Hall told GeekWire.

Boatbound has been around for two years, inked key partnerships with companies like Brunswick and BoatUS, and is operating in several cities nationwide. But with the sun shining, interest has picked up this summer.

Over the last eight weeks, there has been an average of $200,000 a day in bookings planned in a Boatbound marketplace filled with nearly 7,000 boats that cost anywhere from a $50/day canoe to a $1200/day Bayliner.

The Seattle market is also quickly becoming one of the company’s most active metros after just about a year. In the last month alone, it has surpassed Washington D.C. as the most popular new market on Boatbound.

“Word of mouth is spreading and we’re adding more boats in a day than all the other people in this space do in a month,” Hall noted. “We’re quickly becoming the destination people think about when they want to go boating.”

The startup, which employs 14 and has raised $4.2 million, certainly fits in with the growing crop of peer-to-peer services like Uber and Airbnb. With that label comes inevitable questions about insurance and liability. What happens when a renter crashes a boat?

But Boatbound seems to have a solid grip on the safety aspect of its business. Boats listed on Boatbound must meet certain criteria and are covered by the company’s insurance, which includes hull coverage of up to $2,000,000 in addition to a $1,000,000 liability policy. Renters are also screened for criminal convictions and major driving violations.

Hall, a veteran entrepreneur who started three other companies before Boatbound, said he’s a big fan of the sharing economy movement.

“The most exciting thing about what Boatbound and other companies in the sharing economy are doing is bringing back trust and reputation to the forefront as something that matters,” he said. “One day I’d like to see a world where it isn’t your credit report that gives you buying power, it’s your trust factor which you earn by being a good human on sites like Boatbound, Airbnb, and other interactions you have in the real world that collectively rate how trustworthy you are.”

We had a chance to briefly try out the Boatbound experience with Jessica Motais, a Rover.com employee who owns a small motorboat with her husband. Boatbound lets renters either operate the boat — required licenses vary from state to state — or have a captain do all the work.

Motais met us at the Leschi dock just east of downtown Seattle and we set out on a perfect Seattle summer evening.

As we cruised along Lake Washington, Motais posed a question that made my ears perk.

“Do you guys want to see Paul Allen’s helipad?” she asked.

As a GeekWire geek, of course I wanted to see the Microsoft co-founder’s freakin’ floating helipad.

So we jetted south along the water and eventually arrived in front of Allen’s 9.6 acre multi-mansion campus on Mercer Island. Sitting on the water was a giant catamaran that Allen motors out to the middle of Lake Washington in order to land helicopters. Allen wasn’t allowed to build a helipad on land, so naturally, the man built a floating helipad instead.

After getting a glimpse at the catamaran and Allen’s massive property, we jetted back to the dock. As a non-boat owner who hasn’t been on Lake Washington in the summer all that much, it was a lot of fun exploring new parts of Seattle. And with the sun soaking my skin and the wind breezing past my face, it was an extremely relaxing experience — one that definitely had me interested in giving Boatbound a try once again.