here here, now. come sit on me knee and learn. (don't really sit, though

)
1. The mission brief is a SLIGHT mistake. It really should say "Stay 12 miles away from the harbor" instead of the coastline.
2. For your altitude, set for the "medium" preset. It gives you the best visibility range for safe altitude.
3. You do not have to worry about RADAR counter detection, or any for that matter.
4. Although you do not have to detect the subs, if you do, learn to "loft" sonobouys. I will probably make a new topic on that later. (to the hardcore P-3 player: Yes you can "loft" the bouys)
Well, there you go.
P.S: If you really want to know why there is no coastal twelve mile thing, I'll explain to you now.
go into mission editor, (which was used to create the first mission) and be sure that the first thing you notice is how the trigger areas are circles. Now try to make those circles so the edges of them are twelve miles from the coast. After the second or third, you will understand what I am trying to say.