Naya Rivera is missing and presumed dead after she hired a boat with her son on Lake Piru this week.
The lake, which is in Southern California, is notorious for drownings thanks to its hazardous conditions.
The Glee star's four-year-old son Josey was discovered on his own in the boat and told rescuers that his mum had "jumped into the water but didn’t come back up".
Lake Piru is 160ft deep and holds deep columns of chilly water that can overwhelm people, it's claimed.
Naya's boat was in an area estimated to be 30 feet deep with 15 feet visibility.
Steve White, one time Ventura State Beach lifeguard supervisor, said novice swimmers are at particular risk of drowning.
There have been drownings at the lake before as its the only lake you can swim in within Ventura County.
He told the LA Times: "Someone will come to the beach, maybe wade out a little, step into a deeper hole or get picked up in a rip current and they begin to panic."
On top of this, cold temperatures, large waves and rip currents also put swimmers at high risk of drowning.
Strong winds can also tip boat passengers into the water.
Most of those who die are inexperienced swimmers who are not wearing life jackets.
Naya, 33, wasn't wearing her life jacket when she went missing and it was found on the boat with her son.
The search for Naya has been declared a recovery operation by the police, with Naya presumed drowned.
Sgt Donoghue of Ventura County Sheriff's Office said that the search for Naya could take weeks and there's the possibility she may never be found at all.
At a press conference by the lake, he said: "If the body is entangled on something beneath the water, it may never come back up.
"There's no way to really say. We're putting our best foot forward to try and locate her, we're using all the assets that are available to us, we're using technology like sonar."
