This week for Magic Mondays we take you onto the not-quite-so-high seas for a bit of swashbuckling.
This week we give you the Fathomer array.
Notation: Create 100 lumens of Light per cm2 if Stone is within a distance of 1000 times the array’s circumference.
Description: Well “swashbuckling” may have been a bit of an exaggeration. While the Fathomer can’t help you swash your buckles, it can help you continue to do so by ensuring you stay alive. The Fathomer is one of those arrays that you will see wherever you go, yet will rarely pay attention to. These arrays are the silent heroes of the world, keeping us alive and comfortable from the shadows. Noticing a Fathomer is much like noticing the railing on an elevated walkway: you never pay attention to it unless you either need it or it just saved your life.
The Fathomer’s role is to warn whomever is helming the ship of approaching rocks. It unfortunately does not fathom as its name implies, but the fathom of the water can be indirectly determined by the size and shape of the rocks surrounding a vessel and so the mostly-incorrect name stuck. The array does this quite simply by creating an intensely bright light whenever a rock comes within a distance of 1000 times the array’s circumference. Normally the array is carved onto the railings right round the ship at a size of 10cm, so if the ship comes within 100m of a rock sticking out of the water, the arrays will light up. And because the arrays are drawn all around the ship, their fields of effect will overlap meaning more than one will light up if the ship comes too close to a rock. This means that the helmsman can accurately keep track of which direction the rocks lay.
If that isn’t smart enough, the way the sailors have used the Fathomer is. While knowing that you are within a 100m of a rock is very valuable, after the light turns on, what then? Are you within 80m of that rock, or 20m? This is very important as the rock jutting out from the water is only the tip, and it could be much larger under the waves, spelling doom for any vessel coming too close. For this reason, sailors have made variants of the Fathomer, lighting only up if the ship is within 50m, 25m and finally 10m of a rock. To differentiate these arrays, they have fixed coloured lenses over the arrays, with each colour representing a different distance.
Now, no matter how deep the fog is, how dark the night is, or how terrible the storm is, any helmsman can accurately tell the distance and position of any piece of land close to him, making sailing that much safer.