Having trouble getting the brain around..

[fastbikkel]

from a nuclear subsim to a ww2 subsim.

Since i had a lot of trouble with Subcommand in windows 7, i decided to take a break for now and do a ww2 sub sim.
I got a hold of SH4 and i have done one mission for now, without running into ships in visual range.

I seriously am baffled with the change. It will take me a while to realise what needs to be done.

I notice a lot of red targets on the map at certain times. Are these my own radar blips? Or are they notifications from other allied forces?

I never was able to find a ship when i headed for those red blips, thinking the ships was long gone already.
Even at 30k or so, i raced towards a red blip, only to find nothing again.

This is not a complaint, i have the patience to try more things.
I am just a bit careful not to race too hard and end up being spotted too early.

For now i am just reading through the forum here to get some decent info that will help a ww2 sub noob.
Planning is a more important factor now i notice, as i cannot overtake a ship underwater (unlike the nuke subs where i could just open up the throttle to get into a better firing position.)

I travel underwater during the day, only surface at night.

How well does my own radar work? Meaning that i could never find a red blip again after i noticed it on the map just once.

I did notice the sound detections though, some ships were loud enough. I passed two japanese destroyers at reasonable close range, but i was too scared to pop up. I also doubted i could cut them off, they had passed too quick.

Are the red blips, and their little "tail" representative for their direction? I mean, can i plan an intercept course on just one blip?