I think you may have found that canvas people want to FIT the cover to the boat in question so they "Get It Right". Custom covers are just that.. Custom.
I suspect that no two boats are exactly alike..windshield placement..2 inches this way or that...and canvas guys don't want to build to a "floating dimension"...certainly for a $300+ cover. If they build a cover that doesn't fit and the owner isn't happy...SCRAP the cover and do it again. Can't make any money or reputation that way. DJ
Avatar: RELIANCE (1903) The Largest single masted sailing yacht ever built (Until 2004)...with over 16,000 square feet of sail. Successful Americas Cup Defender.
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1986 Minx. SBC 350/260hp, Alpha I. Red, Honey.