If it were a limit of the human eye, the wake would come to a point before you can no longer see it.
It does come to a point before you can no longer see it. It's called the Vanishing Point.
How does the vanishing point allow you to see a narrow mast head of a boat but not the wider hull?
That's not a vanishing point or perspective effect - it must be something else.
Like a horizon on a spherical earth or perhaps light bends . . . for mast heads.
Also, the Vanishing Point is a drawing technique, not a physical phenomenon. You are right when you show that the hull and the masts should disappear at the same time if the vanishing point were a physical phenomenon.
As a drawing technique, the Vanishing Point is widely used when CAD-CAM programs are not available. What Tom Bishop does not want to tell you is that when the technique is taught, its shortcomings are also explained:
- It works nicely only when the drawn object is close to the observer and far away from the horizon.
- When the drawn object is not aligned with the observer, two or even three vanishing points must be used.
- The placement of the vanishing points is not a question of physics, it is a question of aesthetics. Too close and objects seem distorted, too far away and objects do not seem three-dimensional.
- To draw several objects that cover a wide area of the observer's vision, many vanishing points have to be used in creative ways to get an approximate feeling of being surrounded by big objects.
In short, the vanishing point is just a drawing technique designed to make an acceptable approximation of the 3D world in a 2D sheet of paper. It is not a physical phenomenon, not a scientific concept, not an analysis tool. It was not even taken seriously by Tom Bishop himself when "bendy light" had not fallen out of favor.