Matt and Rob, It sounds like the design evolution from the 1970 43’s to the more IOR based 1975/76 42’s the boats lost a bit of reliability downwind. Was it mostly the IOR rewarding max beam more forward and a pinched in stern, a increase in sail area with a reduction on ballast (SA/Displ.), or a little of both?
IIRC the 1970 43 hull design included something called a “high prismatic” ratio. Maybe the swept back keel design makes it more forgiving when pushed hard off the wind. It also has a fuller hull shape aft compared to later IOR designs like the C&C 39. So Rob, what I’m asking is for something like a short study/discussion similar to your “Good Old Boat” magazine Design Comparisons articles. The current issue’s Design Comparison has some good CCA vs IOR discussion but it seems the 1970 43s and 1976 42s are all IOR with no CCA influence. Martin DeYoung Calypso 1971 C&C 43 Port Ludlow/Seattle From: Robert Mazza via CnC-List<mailto:cnc-list@cnc-list.com> Sent: Thursday, March 17, 2022 12:01 PM To: Matthew<mailto:wolf...@erie.net> Cc: Stus-List<mailto:cnc-list@cnc-list.com>; Robert Mazza<mailto:robertlma...@gmail.com> Subject: Stus-List Re: While we wait for spring So, what you are saying Matt, since I was the one steering when we went into that broach on Burlington Bay, that it wasn't my fault! Thank you for that reassurance 40 years after the fact. ;-) However, all those masthead rigged IOR boats were a handful off the wind. However, I remember pegging the speedo at 20 knots on Marauder with the #2 hoisted on the pole in over 30 knots of breeze during the middle distance race in Canada's Cup. The bow wave was breaking at the chainplates. I'd attach a photo taken of the crew at that point but know how that gets held up for approval. Rob
Please trim your messages before sending to the list. Thankx
