On a good clear day...

[Chubster]

at what range should I expect to get visually ID by enemy dd's ?

They seem to be able to see me at +10nm. Playing TMO + RSRD

[BillBam]

What time frame? Later in the war Jap DD's did get some radar so that would make a big difference.

[Chubster]

First Patrol of the war out of Manilla

[BillBam]

On an absolutely clear day 10 nm might be possible. I generally expect them to see me shortly after my crew can see them, if my AI contacts at 8 nm I figure they can see me at 7 nm or so. This is a total guess on my part but I have yet to be detected on the surface using this assumption.

[KlassenT]

Also keep in mind that profile-to-target plays a role as well. Coming at them dead on (So that they would interpret YOUR AoB as 0) gives them much less to work with than if you were strafing across them and they had a full lengthwise view of your sub. This plays an equal role both in visual identification and sonar detection, as I understand it. More surface area means there's both more to be seen and more that sound waves can be bounced off of.

[Werehamster]

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 ;))

[Bilge_Rat]

In RL, the IJN in 41 was very well trained and liberally supplied with excellent binoculars (up to 16x AFAIR). During the night fighting around Guadalcanal, IJN lookouts often spotted Allied ships before the IJN ships showed up on radar. At the battle of Tassafaronga, it was later estimated that the IJN lookouts had spotted the U.S. Task Force at a distance of 20-24 nautical miles, on a moonlit night. Of course, the ships they spotted were cruisers which are considerably bigger than a fleet boat.

[Armistead]

Depends on crew ability and what it's set for, TMO sets many of the escorts to elite or veteran, but RSRD tones down some of those.

On a clear day, don't wait for your crews visual sightings as they are still fresh. They get better as your ratings increase, but like sonar where you can hear much further early war, you yourself can see much further as you're not limited by the crew ratings. Best to do visuals yourself. At night with fog I can get to about 3000 yds on a escort, day...I hang back to my visuals and do a end around and dive.