So if you are landing on a lake on floats or on a large flat area of snow on skis how do you judge height for the flare?
I was taught, variously (for lakes)
(1) look at the shoreline out of the corner of your eye
(2) look down and judge from the waves
(3) sometimes (glassy water, shore a long way off) there's nothing much to go by, so no flare, just descend in the landing attitude.
I got laughed at somewhat by one instructor for doing (2) and then a landplane flare, when I think he wanted me to do (3) (because (2) only works sometimes).
But I didn't have you teaching me, or I'd no doubt know the
right answer :-)