They just wanted to go for a swim. They had no idea what lurked beneath the surface. They never dreamed... that otters attack! And yet ABC 7 reports that for two teenage boys, an idyllic weekend at Lake Shasta turned into a nightmare when they were set upon by a "swarm" of the carnivorous mammals.

"They just kept getting at our legs and our feet," 13-year-old Chris Whitney told the channel. "There was one that kept attacking us no matter what we did."

Whitney and his best bud, 14-year-old Jacob Savage, were out on the water last weekend having fun when things took the frightening turn. "I just remember looking back at it and seeing its teeth," Whitney recounted. "Every time it would go under I knew it was about to attack and it was just so terrible, it's just the scariest thing in my life I've ever been through."

The boys, crying for help, at first went unaided — Chris's dad thought they were just fooling around. "I didn't know they were being bitten at the time," explained Ryan Whitney. "I was actually kind of laughing like, kind of like what the heck is going on."

But for the boys, this was no laughing matter. They were taken to the hospital, given rabies shots, and, according to CBS 5, shown a lineup of otter photos in an effort to identify the perpetrators (this last part really happened, although it was a good-natured ribbing by hospital staff).

The boys are expected to recover, but the three dastardly otters are still out there — lurking just beneath the surface.

Related: Adorable Local Otter Reveals Vicious Thirst For Animal Flesh