I flew floatplanes off salt water in the late 70s and 80 in SE Alaska. We deiced with hot water poured over the wings. Worst case scenario was rain and then dropping temps below freezing over night. We kept planes on ramps then and sometimes had to chip ice off the floats and struts with hammers. Later we got wing and engine covers to put on at night which elimated much of the deicing. These days decreased winter time ops are done with amphibs which are generally hangered over night.
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