Although the hip-deep water meandering down the Santa Clara River looks harmless after last week's rains, it only takes one wrong step to get you killed.
That current of brown frothing water in the usually dry river, and others like it in creeks, streams, arroyos, washes and sloughs across the county, can generate pushing power greater than several strong men.
"With 350 to 500 pounds per square inch pushing against you, even though the water may be only 2 feet deep, it's enough to knock you off your feet and downstream," said Tim Hagel, a senior deputy at the Ventura County Sheriff's Air Unit.
On Sunday, Hagel and two dozen colleagues, comprising more than a third of the Sheriff's Department's swift-water rescue team, practiced their skills on a rain-swollen section of the river west of Santa Paula Airport.
Weekend pilots looked down curiously at two yellow Sheriff's Department helicopters perched on a broad sandbar in the shadow of South Mountain. Rescue swimmers wearing insulating dry-suits, hard plastic helmets and flotation vests took turns drifting with the current toward a fence post positioned in the water.
The wooden post, simulating a log or other large obstacle, would mean big trouble for a rescuer in a real situation. Turbulence generated by water rushing around the barrier tends to pull a person underwater, to drown or be pulverized by rocks on the bottom and large objects carried downstream.
Team members usually float feet-first in a semi-sitting position during rescues, so they spend hours learning how to quickly turn around and pull themselves head-first over unavoidable obstacles.
The current makes for a mean adversary. One rescue swimmer training this weekend was flown from the exercises for a medical examination after being pulled underwater and knocked in the head.
"Even doing things during training is dangerous," said Mark Smitley, the county's swift-water rescue coordinator and trainer.
"When we train, we try to find stuff that's reasonably safe . . . but it can do as much damage."
In addition to obstacles that can drown or smash a swimmer, rescuers must also be constantly wary of getting snagged by branches or ropes, or running into submerged trees, pipes, abandoned cars, shopping carts and other large objects jutting from the bottom.
"You can get severely impaled," Hagel said.
In addition to pulling people from rain-swollen streams and rivers, Ventura County's swift-water rescue team works the stretch of coast from Santa Barbara County to Malibu, plucking anglers swept off jetties and stranded boaters from the ocean. "We get called to around 25 water rescues a year," Hagel said.
Rescuers either rappel to the surface or, when conditions warrant, jump from the aircraft and start swimming, Hagel said.
"The average victim in a flood condition can hang on to a rope no longer than 15 seconds," Hagel said. "You've got 15 seconds for a rescue."
Team members also work other assignments, such as traffic collisions and bank robberies, and Hagel said it's not unusual for the department's swimmers to arrive at crime and accident scenes still wearing their orange and black dry-suits, harnesses and flotation vests.
Sunday's sunny skies made for favorable practice conditions, but several months of wet weather still lie ahead, and officials are working hard to get out the word on water safety. Nearly a year ago, a Moorpark sixth-grader, Joel Burchfield, drowned while attempting to cross the Arroyo Simi, left surging after winter rains.
Hagel said people attempting rescues in fast-moving water should never try to swim after victims.
"Don't jump in--throw them something and call 911," he said.
Hagel said some accidental drownings occur when would-be rescuers are pulled into the water while attempting to haul in victims caught in a strong current.
"You want to make sure the rope is tied to something secure," he said.