Not sure of the game physics, as I am downloading ATM, however, if the moon was behind you, 10 NM, would not at all be surprising for a lookout to get a visual on you, or you, circumstances reversed, to get a visual on a target, in rl, depending on surface conditions. Rough seas, it would be difficult, but on "normal" seas, or flat, calm, the human eye, at night, could detect you. I know, from experience, a lookout during my first Med Cruise in the USN, detected a Soviet Mod-Kashin class DDG at almost 12nm on a flat sea near Italy (distance verified by nav radar, as SPS10 was in standby, under mod EMCON conditions). Seas were 1-3 ft, so, I think (been a long time since me sailor days in Uncle Sugar's Canoe Club!) "normal" is 1-5 ft. Might be wrong on that, but on conservative side..
(Lookout, btw, went from undesignated Seaman Apprentice to BM3 that night
)