ASA 119 is not a prerequisite for any other ASA
classes, it wont help with
insurance, nor will any entity ever want to see your 119
certification.
The StarPath online course is excellent and in
depth. You have access to lots of online resources including the instructors. Highly recommended.
When I tool the StarPath class, I thought I had pretty good amatuer marine weather knowledge. I did most of my own weather routing and usually got it right. The StarPath class bumped that up another level or 2.
Do NOT just buy the book. It is loaded with information and is a great reference, but it could use some editorial
work. Many buy it and never complete it...as did I years before I took the class. The online class, which includes the book, is well worth the
price.
Whichever
route you choose, the real benefit is the knowledge you will gain. Understanding marine weather is very important, especially if you plan any
extended cruising.