Cool!
I remember being on a field trip in the mid 80s on Vancouver island. The fire waterbomber planes they had back then were similar. We got to climb into the tank reservoir part of the plane. Can’t remember the platform…bigger than a Twin Otter, smaller than a Herc.
Edit - quite possibly the Martin Mars waterbomber.
Edit 2: yep, confirmed. Two of the remaining four working out of Sproat Lake near Port Alberni. That’s where we did the field trip (we were on a high school rugby tour that year).