Bar Refaeli shows off her athletic form, frolicking scantily dressed underwater in her latest commercial for Under.Me Lingerie. She was last featured doing manly things.

The Israeli model has been working with the brand to come up with her own designs and she’s been modeling the lines herself in a series of sports-inspired commercials.

She previously appeared playing tennis in underwear. The campaign may be fitting because this is an Olympics year, and there will be lots of publicity surrounding the London games.

Check out Bar’s photos; click to enlarge.

“I feel I look my best when I’m comfortable. Especially when it comes to underwear,” the 27-year-old model says on the Under.Me Web site.

“My underwear is the clothing article closest to my body, and as such, I want it to complement it and not steal the show. There is nothing better than simple, comfortable, quality clothing,” she adds.

My work means I’m travelling all the time, rushing from city to city and wearing the most incredible, elaborate designs. I love it, but on my downtime I just want to relax and be myself.

I don’t want my clothes to define me. And that’s the idea behind – a focused collection of beautifully-made basics that look good and feel amazing. That’s all I need.

“Because underneath my clothes lies the real me. Nothing else,” she coos. Whoo hooo.

Refaeli modeled her men’s underwear line by going through the motions of being a man, including smoking a cigar, mowing the lawn, cleaning the swimming pool and swinging a baseball bat. Oh… and standing in front of a mirror naked.

In this commercial, which seems to have little to do with underwear since Bar is topless and wears a tiny bikini bottom, she’s filmed swimming underwater. She looks oh, so graceful… and sexy. Check it out below, and some screen caps above.