Good follow up Tomoose. You should check and see if you have both Air Search and Surface Search Radar or not. Air contacts don't show up, so if you just check the radar screen you'll know whether it is a surface contact or not.
If you read all of my post, you'll notice I said sometimes the radar does not pick up the Aerial contact and a watchman will spot it instead. Sometimes your radar does pick it up. Sometimes it picks it up too late though.
It might pick it up right before the watch officers spot it, or it may pick it up at long range, or not at all. Why risk not crash diving to find out? You risk the safety of the entire boat by wasting those precious seconds. I'd crash dive anyway. Why risk it?
And yes, in vanilla version you can still see the submarine down to about 100 feet. Go into your graphic settings and turn on environmental effects. You'll see for yourself.
EDIT: I forgot to mention. You'll recharge batteries fastest at a dead-stop, but it isn't economical to do that during a normal sea patrol. Infact, you should avoid dead-stops if at all possible unless you're waiting for a convoy. That's why I said travel at Ahead 1/3 while recharging on normal patrols. Ahead 2/3 gives good fuel economy when not recharging batteries, plus it's less time constraining when traveling long distances. Any faster and your range starts to decrease. Any slower, and you'll waste more time getting there. I did a test once to see how far I could go at all speed settings. Here's what I came up with:
(These are all approximate)
Ahead 1/3: 15,000nm or 150nm for 1% of Fuel
Ahead 2/3: 11,000nm or 110nm for 1% of Fuel
Ahead Standard: 5,000nm or 50nm
Ahead Full: 4,100nm or 41nm
Ahead Flank: 3,900nm or 39nm (You get the idea, so that's something to keep in mind)
This is for Classes: Gar, Tambor, Gato, Balao, Salmon, Sargo
I plan everything lol, but I don't die either
