How Much of My Graticule is Covered With Water?

[scatmania]

I'm a moderately-keen geohasher, as you might be aware if you follow my geohashing logs or you saw that video of me going 'hashing earlier this month.

For those that don't know, the skinny version is this: in May 2008 an XKCD comic was published proposing (or at least joking about) a new game

https://danq.me/2018/08/21/graticule-water-coverage-calculator/