I've oft wondered why the Bombardier CL-415 was discounted. WS was the Australian agent in the mid 90's and tried to generate interest, without success.
As I understand, it only requires shallow water, can load 6000 litres in seconds.
From the Bombardier web site:Aerospace > Products > Amphibious Aircraft > FAQs
How much distance does the Bombardier 415 take to scoop its load?
The Bombardier 415 is very manoeuvrable. If a body of water is 1,341 metres (4,400 feet) long by 90 metres (300 feet) wide and 2 metres (6 feet) deep, without floating debris, then it is scoopable*. Only 400 metres (1,350 feet) are actually required on the water, the remainder being needed for approach and climb-out. Of course, these distances can be reduced by scooping partial loads or scooping while turning. Speed on the water while scooping is 75 knots. Approximately 10 to 12 seconds are required between touchdown and lift-off to scoop a load.