The Horizon - wanna bet ?

I will try to attach a crude illustration of the well known concept of high objects viewed from out at sea. This site has a weird setup for illustrations, so it might not work for me.

The concept is that a boat out on a calm but big lake , can see two lights on shore, of similar brightness (but lets say different colours).  A red one is on a mountain about 1000 metres high. The pink one is on the beach close to the waterline.

On a flat earth,, the boat could sail away from the shore, and eventually the two lights would fade from view.

In real earth, the shore light disappears at ~5 kilometres, while the red light on the mountain will be visible for a long time.

This is a well observed phenomena by sailors. Any FE 'believers' want to bet that it isnt so ?

That sound like an interesting experiment, i could dismiss the whole "things in the horizon disappear because of perspective" idea. But you should use the same kind of light for the mountain and in shore.
Experiments like this are hard to find on the web because the round earth is an accepted true, imagine a video on you tube titled "experiment that proofs the earth is round" everyone would call it stupid, or at least unnecessary.

On a FE, a light lets say 10m above water lever won't disappear in the distance because of perspective, since the wave size is also subject to perspective 

I live near a lake that is roughly 7 km wide and 38 km long. The main harbours are equipped with a strong orange blinking light that is switched on when strong wind is forecasted within short time, as a warning. The lights are between 5 and 10 meters above water level. At night and if there's no rain or fog, when you stand a few meters above the lake, you would be able to see all of these lights from any point of the shore, if the Earth was flat.
But you don't.

That sound like an interesting experiment, i could dismiss the whole "things in the horizon disappear because of perspective" idea. But you should use the same kind of light for the mountain and in shore.
Experiments like this are hard to find on the web because the round earth is an accepted true, imagine a video on you tube titled "experiment that proofs the earth is round" everyone would call it stupid, or at least unnecessary.

Its not a 'strange experiment' - its something that thousands upon thousands of people have observed over hundreds of years.

To make it even weirder, the lookout in the top of the mast ( crows nest ), can often see the shore light while those on deck, cannot.

This is why you see the masts of a sailing ship long before the hull when observing a ship approaching port to those on land.

There are no flat earth navigators, civil engineers, aeroplane route planners, and people who actually have to work with the real world every day. They don't have the luxury of messing with myth and legend.

Also, some of the worlds long bridges in Japan, over 5 kilometres long, have to compensate for the curve of the earth in their construction calculations. Lasers produce totally straight beams for over 15 kilometres.

Obviously no sailors in  the FE world. I guess there cant be, since all navigational maps are spherically derived.

If a FE sailor was lost at sea, I bet I know what sort of maps he would be using to save his life