06/06/2016 09:18 EDT | Updated 06/07/2017 01:12 EDT

Chopper to rescue after Alberta rafters misjudge lazy river float

OLDS, Alta. — Three rafters had to be rescued by helicopter after they miscalculated how much time it would take to float down a slow-moving central Alberta river.

RCMP say the trio — a male and two females from Olds — launched their raft on the Little Red Deer River around 5:30 p.m. Sunday for what they thought would be a two-hour float to the Red Lodge camping area.

A waiting relative grew concerned when they were overdue by three hours.

Attempts to locate them along the shoreline were unsuccessful and the Calgary police chopper was eventually called in to help local search and rescue personnel.

The aircraft located the three around 1:30 a.m. today and carried them to safety.

None of the rafters was hurt but one of them — a woman in her 50s — was treated for mild hypothermia.

The temperature in Olds at the time of rescue was about 10 degrees C. and the wind speed was 11 kilometres per hour.

Police say the meandering nature of the Little Red Deer River effectively doubled the perceived distance the rafters needed to travel to reach their destination.

They also said the river currently has an average depth of 15 centimetres and rafters would need to get out and walk in some spots to pull their craft through.

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