Blanchard Ryan is swimming with sharks in Open Water, her first starring role in a feature film. In order to portray her role as Susan, Ryan had to earn a scuba certification and spend hours in the water with real bull sharks, all while fighting her natural urge for self-preservation. Ryan explains why she decided to forego the fear factor and dive right into the risky project.

"I couldn’t resist. I knew I probably should [be more worried about the danger]," Ryan admits. "When I was trying to make the final decision I was saying, ‘Two unknown actors carrying this movie all by ourselves, taking my clothes off, swimming with sharks and missing out on work at home that did pay (actors on indie projects sometimes agree to waive payment for their work until the film is picked up by a studio)." Yet after weighing all the options, Ryan admits, "I had a feeling that if I didn’t do it, I was going to regret it for the rest of my life."

Based on true events, Open Water follows Susan and Daniel (Daniel Travis), a couple of young workaholics who hastily plan a vacation to the islands. While the two are on a scuba trip, they’re left stranded in deep-water reefs by mistake and soon realize that they’re floating hors d’oeuvres for all that lurks in the ocean. As they bob on the surface of the tidal expanse, the couple begins to sweat bullets when man-eating sharks literally pop in for a snack.

Born and raised in New Hampshire, Ryan got her BA from the University of New Hampshire, then moved to New York City to launch her career in commercials while honing her acting and improv skills. Prior to Open Water, Ryan appeared on the big screen in Broken Lizard’s Super Troopers, as well as on select episodes of "Sex and the City" and "Late Night with Conan O’Brien."

In Open Water, the actress’s cold-blooded supporting cast was considered to be accustomed to humans, but a shark’s bite has a pressure of thousands of pounds per square inch — and the human cast was constantly aware of this. Ryan recalls the danger of working around the unpredictable tuna-fed predators while avoiding an inadvertent role on the Discovery Channel’s "Shark Week."

"If anything, I’m less afraid," says Ryan after working with her sharp-toothed co-stars. "I can honestly say [that] we were in a feeding frenzy with 50 sharks, with blood and scales all over us. It sure convinced me that my fear is down a tiny little notch. The most fascinating part is you don’t know how you would really react," says Ryan about a real-life shark attack.

A heightened level of safety is always paramount on the set of any production, and being immersed in shark-filled waters kicked the threshold up even further on the Open Water shoot. For predatory protection, Ryan and her co-star wore protective chain mail diving armor underneath their wetsuits at all times. According to the actress, it was a small price to pay.

"It cuts into you, like your elbows and the backs of your knees. It’s not the most comfortable [outfit]. You usually wear it over your wetsuit, but we couldn’t because we were in costume. We couldn’t have it showing," she says. "Having it compressed under your wetsuit is not an ideal fit."

Ill-fitting wardrobes and swimming through chum-lines behind her, Ryan has only good things to say about working on Open Water and its supporting cast. "I’m so proud of it. Chris Kentis and Laura Lau (the director and producer, respectively) maintained their integrity throughout this whole process. It’s something to be admired," she says.

Obvious reasons aside, Ryan also had to break through a personal preference for acting on terra firma. "I never went into the ocean over my ankles [before this film]. I knew too much about sharks; they feed in like four to eight feet of water. I’ll never swim off the beach — never would before this movie and never will after," she says.

Looking ahead, Ryan has no doubt about the geographic location of her following gig. "I got just one word to describe my next job: indoors."

Open Water is currently playing in Los Angeles and opens nationally Aug. 20.