Much of the information within on creating a variety of healthy, sustainable food systems aboard a boat is fantastic and ripe with possibility. I, for one, have been sold on testing the concept of making sprouts a cornerstone of the diet and have a batch each of adzuki, kidney, and garbanzo beans sprouting as I write. I'm also quite curious to try crafting a solar dehydrator and oven from the directions provided and may even look back into spearfishing (after an unsettling first experience a few years ago in which the only catch was very nearly that of a snaggle-toothed moray acquiring several of my fingers).
Missing stars are due primarily to two of the author's omnipresent worldviews getting in the way of absorbing and processing the useful information: firstly, that global societal breakdown is impending (he's a seafaring prepper), and secondly, a sort of New Age philosophy that causes him to refer to food as things like "divine light energy". Many of the resources listed for acquiring useful foods and tools are no longer available or relevant, too, due to the book being published 40 years ago.
In short, it's still a very worthwhile read (even for those whose aspirations only reach landwards), but be prepared to skim long-winded passages prophesying the end times/higher planes of existence.