You said that its peak is 130m high and the spur on the far left is 30-40m high.
The pixels of island image in your video is as in the following.
The peak is 273 pixels and the spur is 31 pixels from horizon.
There's a little bit of inferior mirage so the horizon is appears slightly lower than it actually is; but only slightly so okay. Good enough.
Then the obscured height is about 20m.
I don't know how you did that. The refracted hidden calculation on a globe earth viewing from 3m at a distance of 26500m is 26.4m, so however it is you measured 20m as the obscured height, it under calculates by about 6m. Not bad, actually.
If eye level is 2m and wave height is 1m and the horizon distance is about 7.4km
then the obscured height is about 78m.
The eye level height was 3m, making the globe earth refracted horizon 6.7km and obscured height (another ~20km beyond the horizon) 26m.
How are you calculating horizon distance and obscured height on your flat earth?
But If eye level is 5m and wave height is 1m and the horizon distance is about 11.7km
then the obscured height is about 50m.
But if the horizon distance is farther away, the obscured height is even less.
Globe earth horizon distance and obscured heights are different from what you calculated for your flat earth, but the trend is the same. Increasing eye level height increases horizon distance and reduces obscured height. Wave height does not factor in the equation. I'd still like to know how you are arriving at your horizon distance and obscured height figures.
In short, The obscured height depends on eye level and wave height and horizon distance.
But how? The obscured height depends on eye level, which determines horizon distance. But where does wave height factor in?
In short, The obscured height depends on eye level and wave height and horizon distance.
Horizon distance depends on the resolution and ID curve accuracy.
But how? Are you saying the horizon distance changes with improved resolution? Can you zoom the horizon out to 26+ km from a viewing height of 3m? I dare anyone to show me that.
Wave height and resolution are essentially non-factors in what is or is not hidden. I can take photos of that view from that vantage point at different zoom lengths and under varying wave conditions and it won't change. Visibility and atmospheric refractive conditions (like mirage or looming/sinking) will change what we see, but not waves on the horizon nor resolution. I can't zoom the hidden part of that island back into view, and in all my life I've never seen waves of any size hiding that island or even the spur on the south end. The proof of your claim is not in the pudding.
Reflection of light should also be considered.
So it is complex visual phenomena.
More research is needed in the future.
Anyway your video can be fully explained on the flat earth.
I'm not seeing it. No 1m wave on the horizon is obscuring anywhere close to 100m of that island. The wave heights are less today. If I go out and photograph/video the island from the same location, it won't appear any differently. There won't be any less obscured. Wave heights have so little to do with how much of that island is obscured it is undiscernable