I had a chance to assist to one of the those guy training, they work for fire management (SOPFEU) here in Quebec.

The guys knew we'd be there and where. We were on the edge of a very small lake, maybe 2km long. Then they arrived. They dived almost vertically into the lake, only to right themselves at the last second. Then they drew in the water as they came towards us and lifted the aircraft right above us all. 

Then they circled around to come back towards us and dropped the water right in front of us so that only a few drops were left to fall on us.