Dumb question...

[Andy_MKST]

On FM 30-50 diagrams, like this one

What does the "Horizon Beyond the Ship <-> Ship Beyond the Horizon" line represent?

Andy

[herwin]

ORIGINAL: Andy_MKST

On FM 30-50 diagrams, like this one

What does the "Horizon Beyond the Ship <-> Ship Beyond the Horizon" line represent?

Andy

The ship may be closer than the horizon, so the horizon may be seen behind it. It may also be somewhat hidden by a nearer horizon, so that only part of the ship can be seen.

[Andy_MKST]

Thanks Herwin, so how does that tie up to the thickness of the line?

The think and thin parts of the line are 100 foot marks? So why label the ends like that?

[herwin]

Ship beyond the horizon is 'hull down'. There's an equation for how far a ship can be seen as a function of the observer height. Horizon beyond the ship is 'hull up'. There's a corresponding equation. I suspect it's that.

The thick and thin segments allow you to measure along the ship--I guess.