48 N is a good place to start. Also depends on where you live.
Windworks has costal nav and so does Starpath Navigation.
Sail and Power Squadron really depends on the teacher most of them are volunteers. I did not have much luck with the Costal that my local Sail and Power squardon offered. There are classes online and you can study at your own pace. Kevin Wilso from ISPA in Parksville Canada has a wonderful course.
email is email@example.com
Kevin is an accomplised sailor and teacher and I have made an ocean crossing with him . He has worked on this programme for some time . .The web site is www.ispa.com
I hope this helps
Fair Winds to you