Simply: HELPFULL
I am very keen on sailing ships (scale models with Radio Control eqp.). As a non english speaking person I often need some clarification of terms hrom this "special field". That was a reson why I bought this book.
The book itself is very nice and very full of terms and nice BW drawings. It can be used as a real explanatory dictionary but I often take it in to my bed as a book. I read few terms and I have nice dreams then.
I can recomend this book to all who are interested in ships generaly. Definitely it is the book which will not only lie in a book shelf.