I bought this in conjunction with Peter Compton's book. I like booth. Calder is more detailed and more informative, but I find Compton easier to understand and more direct. If I have an engine problem I might start with Compton's book to narrow the possibilites down and Calder's book for detailed explanation. This book is somewhat redundant with Calder's "Boatowner's Mechanical and Electrical Manual" which is definitely a must have. Overall, great book and well worth the money. Would I buy again? Definitely