risk reduced by checking the weather forecast (making arrangements to end fieldwork early if needed), wearing waterproof clothing, wearing warm clothes under waterproofs and bringing a spare change of clothes.
Drowning in deep, fastflowing water:
risk reduced by teacher checking the depth of the water with a meter stick, instructor carrying a throw-in line in case someone falls in, and a safety rope being tied 1m above the river surface to provide stabililty as we crossed the river.
Injury due to falling on steep, unstable banks:
wearing sturdy footwear to give support, following teachers' advice about where and how to enter the river, and not standing on the river banks.