PUEBLO COUNTY, Colo. -

It's being called a family outing on Lake Pueblo, that turned tragic.

A man, his wife and their son headed out in a small, inflatable raft, on the west side of Boggs Creek Cove.  Somehow, all three ended up in the water, and officials say only the son was wearing a personal floatation device.

"We're not quite sure what happened to cause them to all be in the water," said Park Operations Manager Brian Kerrigan.  "For a time all three were floating above the surface."

Suddenly, the 43-year-old father disappeared beneath the surface and hasn't been seen since around 4:30 pm.

Kerrigan says there are a lot of hidden dangers in the lake.

"They can include submerged trees, logs, willows on the shore line that may be submerged...anyone of those hazards can grab onto someone's foot and send that person underwater," Kerrigan said.

Searchers from Colorado State Parks and the Pueblo County Sheriff's Office Dive Team are searching the west side of Boggs Creek Cove on the south side of the reservoir.

Despite rescue crews are out searching, that's not keeping people from enjoying the lake.

"No way, not on a beautiful day like this," Brian Ferriter said.

"As long as you are doing what you are suppose to do and you have your life vest, it's safe to go on the water," Corey Smith said.

The water in the area where the man jumped in is about 20 feet deep with a temperature of between 76 and 77 degrees.

Officials say the last drowning at Lake Pueblo happened in 2011.