Not a must, but very helpful for me. I run quite a few boats. Don't always have time to get a tune in open water. Most days I just fire the boat to make sure it runs and let it sit till the race. I will tune during the mill of the first heat. Works for me. For a newbie, you can get into trouble real quick with a 3rd channel needle. They keep clicking away until it dies. You need to learn how to tune your boat before you go and get a 3rd ch needle. It is legal in all NAMBA classes. There is a stipulation in the stock outboard class. You must run the stock needle inline with the third ch needle.
Mike