Members' Online Book: Sail Handling and Rigging Made Easy, Chapter 41 of 42

Carbon Fiber Mast, Costs and Benefits

In the last post I explained why we replaced our old aluminium mast. This post gets to the real meat: How much did carbon fibre cost? And what did we get for that money?

The new mast, excluding some new rigging, cost about US$55,000, as against an aluminum replacement mast, which would have cost about $30,000; a lot of money to us, particularly since it was capital we were spending that came from the sale of our house.To continue reading, please login (top right) or join us.

Fast is fun: Our friend Flax who, with many miles as the owner/skipper of a Swan 41, knows what fast sailing feels like, is in the zone while steering Morgan’s Cloud

What we got for our exstra US$25,000:

  1. The new mast is substantially up-strengthened from standard practice and even from Hall Spars’ standard cruising mast safety margin of 100%. This thing is a bruiser. Just two examples: the boom and vang goose necks, beautifully molded of carbon fibre, are engineered to withstand a full mainsail crash jibe in 30 knot winds. The tube itself is so strong and stiff that running back stays are simply not required for safety, except in very heavy weather, although we do use them to tune sail shape. It would simply not be practical to build a mast this strong in aluminum.
  2. The boat will now stand up to her full jib-topsail and staysail with a single reef in the main (to reduce helm more than heeling) in 22 knots of true wind; that’s nearly 30 knots across the deck—impressive for a comparatively narrow boat with a big rig that only draws six and a half feet. With the old aluminum spar we would have had two reefs and at least 30 percent of the jib-topsail rolled up in those conditions. More sail set combined with the reduced pitching moment of the rig drives her through a good sized sea at a steady seven to eight knots instead of being knocked back every so often to below six knots by larger waves, as she would have been with the old mast. Her leeway is also reduced a good two to three degrees.
  3. If we are sailing for comfort and not speed, we can carry the same amount of sail that we used to, but heel and pitch less, and still go faster with less leeway. Morgan’s Cloud was always an easily driven boat with a soft and comfortable motion (important for a short-handed crew) and now she is even more so.
  4. We can keep sailing substantially longer in light air and waves before needing to start the engine, because she does not roll as far, which means the sails stay full, which means she goes faster, which means that she pitches and rolls less…yes, another one of those virtuous circles.
  5. We no longer need to use the running back stays to keep the mast up. I can’t tell you how great this is after years of tending to that bane of the cutter rig. We sail a lot more in confined waters than we used to because of this one benefit.
  6. With the environmental issues surrounding anodizing of large structures, most larger aluminum masts are now painted and we all know how hard it is to keep paint on aluminum. My guess is the paint will last twice as long on our carbon mast; not a trivial benefit when you consider that painting our aluminum mast would have cost in the region of US$10,000. Not only that, repainting a carbon mast will be substantially cheaper than doing the same to one of aluminum due to the much smaller amount of preparation required.
  7. The replacement of the aluminum mast with carbon has substantially raised the boat’s limit of positive stability and lowered her inverted stability. In other words, it would take a lot more to knock her down or roll her and a lot less to right her from an inverted position. (Actually, it’s a little more complicated than that.)

The only drawback with our new carbon fibre mast is that when offshore and lack of wind finally does force us to motor, the boat’s motion is noticeably faster and jerkier, to the point that I have felt seasick in conditions that would not have bothered me with the slower and deeper roll of the old mast—in boats, like in life, there is always a trade off.

Our friend Erik, whose sailing experience covers everything from a Dana 24 to big schooners, is impressed as Morgan’s Cloud effortlessly accelerates to the high eights in a puff

So if we had to do it again, would we choose carbon over aluminum? You bet, as long as we had to replace the existing mast anyway. Would we replace a perfectly good aluminum mast with carbon? No, but we certainly wouldn’t scorn someone with deeper pockets than us who did.

If you are considering replacing your boat to get better performance, turbo charging her with a carbon stick instead may be a bargain, but only if the boat in question is a good sailor—no amount of carbon will make a real woofer fly. Morgan’s Cloud was already a fast boat with the old mast and as such she has benefited hugely from her new carbon mast. Enough that I’m tempted to try out her new turn of speed on the race course. But, as I tell Phyllis, I’m all done with that racing foolishness—well, maybe just once more…

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Meet the Author


John was born and brought up in Bermuda and started sailing as a child, racing locally and offshore before turning to cruising. He has sailed over 100,000 miles, most of it on his McCurdy & Rhodes 56, Morgan's Cloud, including eight ocean races to Bermuda, culminating in winning his class twice in the Newport Bermuda Race. He has skippered a series of voyages in the North Atlantic, the majority of which have been to the high latitudes. John has been helping others go voyaging by sharing his experience for twenty years, first in yachting magazines and, for the last 12 years, as co-editor/publisher of AAC.