They plunge into chilly waters, submerging with one purpose, to bring peace to families haunted by the unknown. They're a national underwater search team that goes to work when everyone else has given up.

They're called the Canadian Amphibious Search Team (CAST). When families presume a love one has drowned, and officials have given up searching, they volunteer their diving expertise to recover the body.

"We get integrated with the family and their feeling," said Ken Lugg, one of the divers with CAST. "And we do try to stay objective - but once we obtain our goal the divers are very very happy."

The Winnipeg based group of volunteer divers is often viewed as the last hope for families.

"[What we do] allows many people to have closure and go through the grief process," Lugg told CTV News. "Most families are very upset; but it's with tears of joy because they have their family member back."

In 2005 Heather Howie's family needed CAST. She didn't want to go into detail about her loved one, or how the tragedy happened, the emotions are still too raw. But she did tell CTV News that CAST gave her some reassurance, some hope, and some direction at the height of her tragedy.

"It's very hard to know that there is someone missing; and that you aren't able to help them or find them," she said.

The team isn't always successful, but when they are, families can finally lay their missing to rest, and find closure at last.

CAST spent this Saturday and Sunday at West Hawk Lake practicing body recovery.

They polished up their ice diving skills by helping train another rescue team from British Colombia.

"It's important to get cross training with other teams," Scott Strickland of the Okanagan Dive Rescue Team said. "And it's an asset to train with a team that's been around for a while."

The CAST team responds to request from Alberta to Manitoba/>/>.   In the last six years, CAST has been on 15 missions, 11 of those were successful.