Ultimate Survival Alaska - Season 3 Episode 2 -

On leg four, teams travel by land and water, as they charge toward the extraction LZ on an ocean inlet. The adventurers choose to either take boats down one of the most notoriously dangerous rivers in Alaska, or make a grueling trek over a mountain pass. The Alaskans take two inflatable canoes down the deadly rapids. Barely making it out alive, the Alaskan vets attempt to ride a massive tidal wave known as the Turnagain Arm bore tide.