So What's the SA/D Ratio of the Far Reach?

Discussions about Cape Dory, Intrepid and Robinhood sailboats and how we use them. Got questions? Have answers? Provide them here.

Moderator: Jim Walsh

Post Reply
John Stone
Posts: 3623
Joined: Oct 6th, '08, 07:30
Location: S/V Far Reach: CD 36 #61 www.farreachvoayges.net www.farreachvoyages.com

So What's the SA/D Ratio of the Far Reach?

Post by John Stone »

We moved the boat today as part of a boatyard shuffle. By the way, we launch Wednesday morning as we prepare for our next voyage. Removed the cover yesterday. Hooray!

Anyway, I was told today the boat weighs 14,500 lbs. So, was interested in the SA/D ratio and thought I would share the numbers.

The FR weighs less than I thought she would. A stock CD unloaded but with fuel and water displaces about 16,100 lbs. The FR has a smaller engine, smaller fuel tank, lighter rig, no wheel steering, gobs less wiring, no furler, almost no systems, and all kinds of other stuff removed. She has about 30 gallons of water onboard her today (we have 95 gallons of tankage) so that's about 500 lbs less in water weight than she would normally carry. No sails on the boat, but she has the dinghy aboard plus dodger, windlass, solar panels, windvane, some tools, etc. So, I figure she displaces about 15,000 wet if compared straight up to a stock 36. That's still 1,100lbs less than a stock 36. That surprises me. Remember, I added the bulwarks and bronze gallows frame. But I also l cut out the fiberglass headliner during the rebuild and as I mentioned removed all those systems. That's the second time the travel lift operators have given me that number (14,500 lbs) and with two different travel lifts. So, perhaps it's close.

Because the FR has a taller rig and longer bow sprit her sail area (main plus 100 percent fore triangle) is 779 sq ft vs 622 for a stock 36.

A stock CD 36 at 16,100 lbs has a SA/D of 15.8. Just about all Alberg's boats are about 15.7-.8 and they perform well in my opinion.

However, at 15,000lbs the SA/D of the Far Reach is 20.5
I figure 17,500 lbs fully loaded for voyaging. That's a SA/D ratio of 18.5 and it's the fully loaded displacement we should be interested in knowing.

Out of curiosity I ran one more number--actual working sail area of main, our 100 percent jib and stays'l is 963 sq feet for a true SA/D of 22.8 in fighting trim if 17,500 lbs.

Though our CD boats handle additional weight well compared to lighter built fin keel boats, weight relative to sail area still matters especially for light air sailing and maneuverability. Every pound we add to our boats adds up and eventually comes at the cost of diminishing performance under sail.
You do not have the required permissions to view the files attached to this post.
Last edited by John Stone on Nov 13th, '21, 22:23, edited 1 time in total.
User avatar
mgphl52
Posts: 1809
Joined: Feb 6th, '05, 14:15
Location: s/v KAYLA CD 28 #318
Contact:

Re: So What's the SA/D Ratio of the Far Reach?

Post by mgphl52 »

Very interesting numbers! Thanks for sharing with the board.
-michael & Toni CDSOA #789
s/v KAYLA CD28 #318
2012 FLSTC Heritage Classic
Niceville FL
+30° 30' 24.60", -86° 26' 32.10"
"Just because it worked, doesn't mean it works." -me
No shirt + No shorts = No problem!
Post Reply