Open Waters.
Its been in the pool since ages but it doesnt work, game simply wont launch.
When you try to host this map directly from FAF lobby, you get an error message that scenario.lua is missing and cant select it from the game lobby.
Pretty sure the one who uploaded map to the vault just fucked up, would be nice to see it deleted since it doesnt work.
The fix is very simple, there is a working version in the vault called Open Waters v2 (NOT 20km), just need to use that one.