This is a complicated subject so some book study and practical experimentation is needed:
World cruising routes / Jimmy Cornell. I ordered my copy of this book used from alibris.com.
The global site for cruising sailors — Noonsite
"The global site for cruising sailors" started after publication of books
by Jimmy Cornell.
"Noonsite's main objective is to provide cruising sailors with comprehensive information regarding essential marine
facilities in any port visited by yachts".
Ocean Passages and Landfalls / Rod Heikell
More descriptive of landfalls, less dry than above book says Amazon reviews
/ Mike Pyzel is available from the publisher of this book, Northern Breezes, 3949 Winnetka Ave N, New Hope, MN 55427, Phone
: (763) 542-9707. This book is used for the American Sailing Association coastal navigation
course. It is written well enough that a person can do self study in my humble opinion (IMHO). The cost is about $35. The only other book I know of that comes close is Practical Navigation by W.S. Kals written about 40 years ago available again from alibris.com. Kals also wrote Practical Boating
, Inland and Offshore
Power and Sail that has additional information on navigation and other topics of interest.
Coastal Navigation Course - ASA 105 Certification - American Sailing Association Standard
Find a Sailing School - Learn how to sail with sailing instructions from American Sailing Association.
The coastal navigation course will help you plan your trips. The principles are the same whether sail or power except that you need to know miles per hour and the amount of fuel burned for different revolutions per minute (RPM) of the engines. Find propeller
curve data for engines used in your boat for RPM
vs. gallons per hour used. Google
under manufacturers name and “marine engines”. Pick a calm day with no tidal or ocean current
influences and do speed runs with the GPS
in both directions and take an average. Also do runs with wind
to see what difference that makes in speed. Check the winds at weather
.gov after you make the runs to get actual data, not forecasted data, or better yet, use an anemometer on the boat to get wind speed. Before you go on any long voyage, a diver needs to clean the hull
for best economy, and therefore, the tables developed for RPM
, fuel burn and speed should be done with a clean hull
. A dirty hull and propeller can use one third extra fuel and more. Or, you could do your speed runs just after the boat has been pulled for new bottom paint
and propeller cleaning
. Oddly enough, the wax used on surfboards to make ones feet stick to the board works well to keep barnacles
off the propellers. A few barnacles
can really have an impact on fuel economy especially if on the leading edge of the propellers.
The above books
can give you some idea of conditions you will encounter such as ocean currents and winds that will influence fuel consumption
. However, while actually underway you need to check your miles per gallon by dividing GPS
speed by gallons per hour burned. With the amount burned per hour, you can also figure hours of fuel left by dividing fuel left in tanks
by gallons per hour burned. To determine fuel left, you need to keep a log of running times for various RPM setting you used and therefore amount of fuel used. Take hours left times speed and you have your range. Try different RPM settings for best range to see if you have enough fuel to make your destination
with some reserve.