You have to go to the orange star and remain there till it turns gray.
You will get a message at that time letting you know you suceeded.
Personally, I call that a dumb mission cause no captain worth his salt
would take his boat thru there in the daytime. Shallow water in daytime
is a bigger enemy than all the Japanese ships & planes combined. You are
a fly in a spider web, no way out...
JIM
PS. Try one of my patrols, they are much better than most of the stock stuff.
http://hosted.filefront.com/FAdmiral/