It's OK for some....it should give some newbies an idea what to be considering for sure....
Probably too complex or difficult to use for some and for others with some cruising experience that tracked their expenses a bit too simplistic or just a different way of looking at costs.
After 2 four month trips from NJ to FL tracking every cent, and studying marina costs as well as misc regional type costs such as average restaurant, grocery, entertainment, pumpout, etc...etc costs it would be easy to plug into many different budgeting spreadsheets.
But I like to look at it a different way....once I established a reasonable weekly budget when cruising....that average is what I use. If I feel like going above or below to push expenses off or splurge on something...I have a pretty good idea of what my 4 month trip will be or could be depending on my game plan. For the most part I can now plan to hit that average in my head, and rest assured my numbers have contingencies in them too....plus as I venture I to more or less expensive regions, I either adjust or splurge or add to the reserve.
So all in all, a little experience, a little study of regional costs and a way to make it make sense to you is all you need. Use the tool as a basis or develop your own based on how you normally budget...it's really not too complicated.