This video shows Walker Marine Geophysical in southern Chile running a seismic line up the Rio San Pedro to map bedrock for a proposed hydroelectric dam site. The whitewater current is running about 10 knots, the water depth is about 1.5 to 3 meters, and there are a number of very large boulders that had to be navigated around.
The boat was custom built for the survey. It had to be lowered more than 100 meters down a very steep canyon wall and assembled at the base of the cliff. The engines are waterjets for navigating through shallow rapids and protecting the towed geophysical equipment.