The "sinking ship" phenomenon seems to be such a "hot button" item for both FE and RE believers - I'm inclined to just drop that debate and call it a draw.
Shadows cast by the sun is a tricky one too - in RE you'd expect a row of identical sticks stuck in the ground along a meridian line to cast equal length shadows - but the tilt of the Earth's axis complicates that simple idea to the point where you need some fancy (and therefore unconvincing) math to unravel what happens. Similarly in FE, the position of the tiny sun and it's motions are not well described by the available sources (the Wiki, for example) - and the arguments about how sunrises and sunsets can happen are also somewhat flakey.
So that too is an area of debate that's hard to nail down.
I think the proof here lies in things like travel times and ranges of aircraft in the Southern regions - which are all subject to easy examination and super-simple measurements on available maps.
The motion of the stars close to and south of the equator is similarly easy to examine - and produces serious problems for FE theory. There are PLENTY of time-lapse videos made by private individuals - along with a wealth of personal experience which are hard to deny as evidence.
My personal favorite is the phenomenon of there being two high tides and two low tides per day in the oceans of the world - which FE theory simply cannot explain.
The phases of the moon - and the simple observation of shadows cast within lunar craters makes for VERY tough problems for FE.
These seem to be the places where "proof" is to be found.
Of course, the FE proponents are reluctant to discuss these things - and simply vanish from threads when they don't have a good answer - rather than admitting that their theory needs work in order to remain credible. Some intellectual honesty about such matters would be refreshing.
Additional problematic things - such as how FE theory can explain how objects fall to Earth when you drop them, are tricky to address because there are MULTIPLE FE theories attempting to explain them...and until you figure out which of these theories each FE proponent follows, debate can be quite tricky. Here, their common mantra of "READ THE WIKI" fails because that tends to present just one (or very rarely, two) theories to explain a particular phenomenon - and in reality, their members here and elsewhere do not seem to follow those theories unanimously.
That's fine - people will clearly have differing views - but it can make debate difficult.
Still - I'd very much welcome some simple, informed debate - with both sides being respectful of the other's views - and with both sides remaining engaged in the discussion until either one side or the other is demonstrated to be correct...and clearly difficult topics for one side or the other can be explored - and perhaps either FE theory or RE theory may be found wanting and demand further thought.
But good debate seems hard to find around here - which is unfortunate.