I watched enough to notice these guys math is WAY off. like really far off maybe someone forgot to multiply the 5280 to go from miles to feet idk. but if my line of site it 10' from the waterline and for the horizon to hide half a container ship ~50' it has to be really really far away not the 10 miles these braindead idiots are talking about. if your trolling than congradulations for wasting an hour of my time but if your serious i suggest you look into the properties of tangents its pretty simple