The hull of the smaller boat seems to be obscured behind some water too. Look how close the waves get to the deck line:
It's not really that much more depth needed before the little house structure is sticking out of the water like with the big boat.
Correct. The waves do hide some of the small boat, but they would still hide less of the big boat. And the thing about boats is that they float on top of the waves. so if the waves were big enough to hide either boat, it would be intermittent as the boat itself would be rising and falling with the waves. You can see a little of this happening with the small boat, but the waves still never hide the hull of the small boat. Moving the small boat further away on a supposedly flat earth would make the waves and the boat both appear smaller, but it would not change the percentage of the boat appearing above the water (unless of course some other mechanism came into play and hid the hull....such as the curvature of the earth).
Waves that are too small to hide the small boat are way too small to hide the big boat. What is so hard to understand about that?
It is one of the most ridiculous claims of flat earthers that perspective can hide the bottom half of an object before it hides the upper half. Photons of light do not behave in such a ridiculous manner. If there is a line of sight between our eyes and an object, then moving further away does not change that fact. Any object that is above the plane of a flat earth would remain within our line of sight indefinitely up to the point where our eyes can no longer distinguish it from its surroundings, which is not even close to being the case with the larger ship. And even then it would be within our line of sight, so a telescope could bring it back into view. This does not happen as clearly shown in the video I posted earlier in this thread:
Distance does make an object appear smaller, but it does so equally in all directions, so if the bottom half of a ship is in our line of sight, it will still be in our line of site as it moves further away on a flat surface. And as the ship gradually appeared to be smaller, the waves would also gradually appear to be smaller also. Again they would both shrink by the same amount, so if waves cannot hide the smaller, closer ship, then those same waves which would appear smaller at the distance of the larger ship, would not be able to hide such a large portion of the larger ship.
The only explanation that makes sense for why the bottom half of the more distant ship is hidden is that the surface of the water is curved as predicted in a round earth model.