NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Modern designs ( was: De Lurk)
From: Rodney Myrvaagnes
Date: 2003 Feb 11, 08:58 -0500
From: Rodney Myrvaagnes
Date: 2003 Feb 11, 08:58 -0500
Your question is itself oversimplified. If the ability to take sights in a seaway were at the top of an NA's list of priorities, he would probably be able to accommodate a wide range of styling features (above waterline appearance). I doubt this has ever happened. The steadiness would be strongly affected by the moments of inertia in roll and pitch, and by the initial stability (mostly form) in the same motions. But since both the pitch and roll combinations will have natural frequencies, any one design will have some waves it likes, and some it doesn't. Modifying both pich and roll will be damping for both from hull shape. Long overhangs were a response to a rating rule that measured waterline at rest and weighted it heavily. In that sense they are ancestors to the measurement bumps on IOR boats of the 70s and 80s. They are "classic" only because the rating rules that produced them are long past. This discussion started with boats that have been clinker built around the North Sea for ave 1000 years (vis Gokstadt ship, etc) and have as much to do with construction technique as anything else. Canoe sterns on fiberglas boats are a styling reference to these and other ancestral types, a different matter entirely. The last time one appeared on a boat intended to be raced was, AFIK, Bob Direktor's "Wild Goose" from the late 1960s, a CCA design. Adlard Coles in the first edition of his heavy-weather classic had already observed that large buoyant sterns were more survivable in storms than pointy ends. That has not changed. On Tue, 11 Feb 2003 12:51:02 +0100, Axel Vis wrote: >Just out of curiosity: Is a classic design with a narrow stern, large >overhang, v-shaped hull and long keel easier to take a sight on than a >modern wide-bodied yacht? Or is there no real difference. For starters I >can walk away from the helm without my big girl straying from her >course. Owning a classic design is fun but I hate to admit that I am >sometimes envy those flashy racers a bit. > Rodney Myrvaagnes NYC J36 Gjo/a "WooWooism lives" Anon grafitto on the base of the Cuttyhunk breakwater light