I too have admired the
Fire Boss and would love to fly one - that sort of work would be extremely challenging and satisfying. Whilst I'm not an ag pilot I have spent the last two years flying floats - and with absolutely no disrepect intended I will comment on the accident.
The deepest part of an aircraft's floats are located behind the center of gravity of a float plane in a landing attitude. One reason for this is for directional stability whilst on the water. If you land a floatplane with the center of hydrodynamic resistance in front of the centerer of gravity and there is any sideways drift relative to the water the aircraft will yaw/slew extremely violently - this can be seen dramatically in the 1982 film "Mother Lode" (the accident was not scripted), and was also demonstrated a few years ago when a float plane collided with a yacht in Chance Bay in Queensland following a low nose landing where the pilot subsequently lost directional control.
Given the configuration shown in the ATSB report with the skis so far forward it would only require one leg to 'grab' and the result is not at all surprising. A slight turn, a light crosswind or even water conditions may have been enough to start the sequence. If this happens on floats you have a chance of staying upright - with small skis you would become a passenger along for an extremely violent ride.
W
PS Water scooping floats for firefighting are not new - they were a factory option on De Havilland Canada Beavers in the 1950's.
PPS Amphib floats are expensive. The Wipline 10000s as fitted to the Fire Boss are smaller version of the 13000's - a set of 13000 amphibs including fittings costs around $426k US. In Australia it would be extremely difficult to get a return on them.
RIP Col