Down to the Wire - More About Zincs
- By Brett Dingerson
"Do zincs really work?" - The answer is a resounding yes! An oversimplification about how they work has to do with the fact that zinc is low man on the metal food chain, so zinc anodes are "sacrificed" in a process called galvanic corrosion. Investing in zinc therefore will save you laying out a bigger investment in eroding bronze, stainless steel, props, shafts, rudder shafts, thru-hulls, and all the other more expensive words in a mariner's vocabulary.

"How long should my zincs last?" - Every boat has a different demand for zinc anodes to maintain proper protection, but a properly bonded, painted, and maintained boat with properly sized zincs should expect annual replacement. If you're experiencing dramatically shorter zinc life span, there is probably something that needs to be corrected.

One reader asked, "My boat is on a mooring ball, not in a marina, and I also think my zincs are disappearing too fast." One possible reason - fast currents can accelerate zinc usage. This could even be a factor with your slip location in your marina. If you think this may be a factor with your boat, try positioning the zinc in a more protected area. Bonding your boat will also protect you from any onboard stray currents and eliminate those issues.

"I have heard that if you don't use mil-spec zincs, they won't work." - You don't have to use zinc at all for a sacrificial anode, but that's a subject that doesn't matter to the average boater. If you buy a zinc from a qualified marine store it will be "mil-spec" and you can use it.

"I didn't know that if my neighbor's boat's zincs are gone, his stray current could start eating my zincs away - is that true? - How far away can current like that stray?"

Zinc life span and stray current are two separate subjects. If your neighbor's zincs are gone and you are properly isolated it's not going to affect you. If your neighbor has stray current and you are properly bonded and isolated, that's not a problem either. Electrical currents can travel from one end of a marina to the other, but are certainly more severe if you allow your boat to be a piece of the puzzle. So, isolate your boat and bond your boat and you'll be in good shape.

"I understand that one cause of fast zinc erosion is that I may have reverse polarity on one of my 110 volt devices." - That's definitely true, but reverse polarity can also kill you; so the zincs are the least of your problem - get that situation repaired immediately!
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Editor's Note: Brett Dingerson has over 25 years experience as a marine electrician, with a specialty in marine galvanic corrosion protection. He has worked with a wide range of sailing and power vessels and is the owner of San Diego-based Marine Electric. If you have an electrical question for Brett, send e-mail to brett@BlueSkyNews.com

From The Sea Bag - What's In Your On-Board Library?
-By Frank Mowry
Having time to read is a perk we cruisers enjoy, and while on-board nautical libraries vary in content, they generally contain the "must have" technical manuals which guide us through the intricacies of the diesel engine and instruct us how to arrive at San Miguel and not San Pedro; and the "fun to have" which entertain and shorten the long hours downwind when neither wind nor sea state has changed in days.

What follows, are some of my favorites in both categories. Nigel Calder's "Cruising Handbook" has been called "the essential guide for choosing, equipping, and sailing coastal or offshore cruising boats", and I would heartily agree. Mr. Calder has written other helpful books including "How to Read a Nautical Chart" and "Boat Owners Mechanical and Electrical Manual".

The Southern California cruiser should also get to know Brian Fagan. His "Cruising Guide to Central and Southern California" and "Staying Put", an anchoring monograph, are excellent resource documents.

The Southern California Cruisers Guide by the Santa Monica Restoration Commission, contains a wealth of information about major destinations in our cruising area including drawings and superb aerial photographs of major harbors. Another cruising guide of merit is Margo and Charles Wood's "Charts of the US Pacific Coast". Paper charts (and knowing how to apply them) covering your areas of travel should be on all cruising boats. The mantra "never depend on a single navigational method" should not be taken lightly! To compliment your paper charts, Frank Larkin's "Basic Coastal Navigation" contains easy to understand instruction.

But enough of the technical stuff! The cruiser doesn't live by fixes alone! How 'bout the fun stuff to read while underway or bobbing on the hook. By its nature this list is long as your arm and very subjective.

Among the works I favor are Patrick O'Brien's historical novels about the British Navy during the Napoleonic Wars. This is fascinating stuff and written with riveting prose that keeps the reader returning for all 22 volumes! Nicholas Monsarrat's "The Cruel Sea" is a nail biter about sailors in the North Atlantic during WWII.

For the history buff, I can recommend John Keegan's "The Price of Admiralty". He discusses in some detail the four major naval battles that helped change the course of modern history: Trafalgar, The Battle of Jutland, The Battle of Midway, and The Battle of the North Atlantic.

The volumes mentioned and many more "sea stories" can be obtained form Captain Ann at Seabreeze Books and Charts in Point Loma. So much to read, so little time! If you have a favorite you'd like to pass along to our readers, please send me an e-mail and let me know about it.

Frank Mowry Editor's Note: Frank and Martha Mowry have enjoyed cruising southern California waters for 10 years aboard their 42' Island Packet sloop. They are members of the Southwestern Yacht Club. Click Here to send Frank and Martha an e-mail.