The World Naked Bike Ride gets all the attention in Portland, but it's not the only summer event that strips bare in the middle of the city.

Last year the Naked Goddess Swim came to downtown Portland, encouraging "mere mortal women" to "shed their suits and inhibitions to swim as Goddesses in the full moonlight."

The nude, women-only swim will return to town on Saturday, August 20 on the east bank of the Willamette River near the Hawthorne Bridge, expected to attract about 120 participants.

The event started in 2013 as a small, lighthearted affair among 11 friends in the relatively secluded Clackamette Cove in Oregon City. The next year attendance ballooned to 60 women, with another 60 on the waiting list.

But just as it began to blossom, Clackamette Cove began to change. In 2015, Oregon City began developing the cove, shutting down the area to build apartment buildings above the spot where the goddesses swim.

"This event has seemed to strike a nerve and had built momentum without a push, so we kind of didn't want it to end," Malloy said last summer. "It's not going to be this kind of dark and mysterious under-the-moonlight swim that it was at the cove, but I think it's going to be more accessible and festive and vibrant."

Mission accomplished.

With help from the Human Access Project - organizers of the Big Float - the Naked Goddess Swim relocated to the Willamette River in downtown Portland, a spot with more space and far greater access, not to mention more visibility.

Nearly 120 women showed up for the 2016 swim, Malloy said, and all fears about undressing in such a public place faded quickly.

"The women who show up to this are pretty clear about what they're doing, and they don't care" about leering onlookers, she explained. "They're there for other reasons, and those people don't exist to them."

This year, as in years past, the swimmers will be supported by "kayak gods" and "trusted gentlemen" - men (and some women) there to keep the women safe in the water, and comfortable in public.

Organizers require all swimmers to bring personal flotation devices and attend a mandatory safety meeting before getting into the water.

Like the World Naked Bike Ride, one question lingers among those unfamiliar with the swim: Why do these women do it?

When the Naked Goddess Swim first started, it was a fundraiser for Friends of Clackamette Cove, a group that encouraged swimming in the Oregon City cove. Now that it's moved to Portland, and the cove is being developed, the objective is evolving.

"Now it's switched its goal more in alignment with Human Access Project, which is to get people to get into the river and enjoy the river," Malloy said. I'm pleased what it accomplished [at Clackamette Cove], and now the event has almost taken on a life of its own."

Swimmers also have a tendency to choose their own cause. Most common among them is body positivity, a thread common with the Naked Bike Ride.

Whatever the cause, wherever the water, the naked goddesses will swim on, bathing in nothing but the light of the moon.

"To be a naked goddess means that you love your body, you love your shape, you're proud of it, you affirm it - not for anybody else but for yourself," Mallow explained last summer. "This isn't about showing everybody else our body, this is about accepting and affirming our own body."

* * *

NAKED GODDESS SWIM 2016

When: Saturday, Aug. 20, from 9:30 p.m. to 11:30 p.m.

Where: Public Dock on the Eastbank Esplanade (map it)

Registration: $32.64 to swim, register online

--Jamie Hale | jhale@oregonian.com | @HaleJamesB