December 15th, 2017

Several techniques used in search of missing swimmer

By Tim Kalinowski on June 6, 2017.


tkalinowski@medicinehatnews.com
@MHNTimKal

Searchers used a variety of techniques to try to locate a missing man who is believed to have drowned in the South Saskatchewan River last week.

In the early hours of search, rescue crews focused on the shoreline. South East Alberta Search and Rescue provided two ground teams to comb either side of the river, boat crews from SEASAR and the Medicine Hat Fire Service scanned the river. Helicopters provided by HALO and BATUS and a fixed-wing aircraft all scanned further out from immediate search area to see if the young man had, by chance, gone further than search teams expected.

When it was determined the young man had likely not found a way out of the water, ground and aerial searches were suspended to focus on where he might be found under the water. Using marker buoys to chart the current and sidescan sonar to trace the underwater landscape, crews hoped to find the body at the bottom of the river near where he had last been seen. In most cases of drowning in a river, the body is initially dragged to the bottom and pinned there for some period of time before re-emerging.

Deputy fire chief Lance Purcell says the fire department once used to drag the river in attempt to pull a body up from the bottom, but there are several reasons why this practice has been suspended in recent decades.

“First of all, we really don’t know where he is. This is a broad search. We have an area where we were looking at, but to drag the river you have to remember at the bottom there is massive amounts of rocks … If there were just mud on the bottom it would be a little easier, but with rocks and everything else in the river it can pose a hazard to the boat.”

Purcell says improvements in sidescan sonar technology make it more precise than the hit and miss tactics of dragging. Boats equipped with sonar, augmented by search dives, will likely be the main techniques used once river conditions improve enough for operations to resume.

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