To all those who want to know more about propellers in theory and practise:<br /><br />Quicksilver sells a 55 page booklet called 'Everything you need to know about propellers'. <br /><br />Even though they're focusing on their own range of products, it is very good and explanatory for all.<br /><br />Fourth edition (1992) is P/N 90-86144-92. In this booklet is says 'for a copy of this book contact you dealer or send check/money order for $5 to Quicksilver Propeller Book, P.O. Box 3900, Peoria, IL 61614'.