how to save a mission

[PapaG39]

I just started the Scapa Flow mission and made it all the way to the center of the Scapa bay when a DD came out of nowhere & ran right over me...I did blow him to tiny boat parts, but that was while I was sinkin...lol..

Anyway, I tried to make some "saved points" along the way, but none of them took. I have no idea why so could someone be kind enough to go-through the exact procedure so I don't have to start from the beginning again & again...lol

Do you have to have waypoints laid out to save a point? I didn't use way points because I just was trying to stay in the deepest part of the channel...

By the way..Is there a-way to bring up a map with the actual bottom plotted so you can se where these deepest areas are???