As your aircraft climbed, you were simply able to overcome the limitations of your vision. Please refer to Earth Not a Globe, Chapter 14: https://www.sacred-texts.com/earth/za/za32.htm
Hogwash... that video is not from my eye... it is taken with a camera at 12x zoom. None of what you are seeing in the video is a limitation of the human eye.
"At these times it appears close to the horizon where the density of the air differs greatly. The air near the ground is denser than the layer of air just above it, and the layer of air above that is less dense still, and so on upwards until the Earth's atmosphere peters out at some 400 km. Now consider what happens when the Sun is setting. When the Sun is at the horizon, light from the top of the disc is going through the air at a different angle than that from the lower part. So the rays are bent by different amounts before they reach the observer's eye."
If it were a matter of air density, then the shape of the sun would still be visible, only more dim in the thicker air and brighter in thin air. This is why a setting sun become more orange and more dim as you view it through more air when it is close to the horizon. However, the earth blocking it as it goes below the horizon is a complete shutout of the light and changes the shape of the viewable sun.
And more specific to your particular line of enquiry:
"Those who believe that the earth is a globe have often sought to prove it to be so by quoting the fact that when the ship's hull has disappeared, if an observer ascends to a higher position the hull again becomes visible. But this, is logically premature; such a result arises simply from the fact that on raising his position the eye-line recedes further over the water before it forms the angle of one minute of a degree, and this includes and brings back the hull within the vanishing point."
In figure 83, they have been deceptive. If we are supposing a flat earth, there should be no rise in the water in that diagram. It is cleverly done to make a bad point but furthermore only reinforces that the earth is round by showing that there is a difference in perspective elevation based on distance.
That all being said.... My video is NOT of a sailboat on the surface of the ocean. It is of the sun setting behind the horizon as we are flying TOWARDS it at nearly 500 MPH, and then coming back into full view as we gain altitude.
None of what you quoted disputes any of my video, do you have any thoughts of your own?