OK
I'll bite.? Here's the nav arch answer to OB vs IB For a catalina 27 at even keel at DWL: The weight required to sink a catalina 1" (aka TP1") is approx 0.26 ltons, or 600lbs The moment required to change trim 1" is approximately 650 ft lbs The increase in wetted surface for every 1" of immersion is 4.5 sq ft, or about 3% The?LCF is 1.2ft aft of amidships, or slightly less than 10' forward of the transom an 80lb 9.9hp OMC on the transom will generate 1.2" of trim by the stern a 245lb atomic 4 located 5.5ft forward of the transom will generate 2" of trim by the stern and sink the boat about 0.25 " further than the OB So in the end (no pun intended) the OB causes less "squatt" than the inboard and saves on total weight and wetted surface.? Since the transom is still out of the water at these loads there is no measurable difference in LWL. As for ballast, the chain locker is about 13ft forward of the LCF, so if you want to have a permanent offset to 300lbs of crew located in the cockpit (about 6-7' aft of LCF) you would require about 150# to generate the countervailing trimming moment. OK, clearly it's a slow day Happy Holidays to all Peter Zahn Snagglepuss #2622 -----Original Message----- From: [EMAIL PROTECTED] To: [email protected] Sent: Thu, 20 Dec 2007 10:44 pm Subject: Re: catalina27-talk: Race Sails & Ballast/IB v OB Oh man - Here we go again.? I'll take my outboard any day. ? In a message dated 12/20/2007 10:16:57 P.M. Eastern Standard Time, [EMAIL PROTECTED] writes: In a message dated 12/20/2007 12:09:34 P.M. Eastern Standard Time, [EMAIL PROTECTED] writes: ????This is all speculation, but I believe when Frank designed the hull, it was for an outboard and a tiller. So the addition on a much heavier inboard and wheel (the wheel, also moving you aft) will make the stern squat. This is obviously not ideal, but IMO makes for a much nicer boat. Also, you can add enough weight to the bow to nearly sink the thing, and the stern will still squat at hull speed as it falls into the bow wave. I feel the best option, if it bothers you,?is to move all your "stuff" forward, including the batteries, but never ADD weight to any boat unless it is a cargo ship. ? Tommy, See AOL's top rated recipes and easy ways to stay in shape for winter. My inboard weighs 245 pounds and is at the fwd end of the cockpit. How much does that 9.9 weigh hanging way back?on the transom? Can you say Torque? Most of the time, when the auto pilot isn't engaged, I steer from the fwd side of the wheel. The only drawback to an IB is the drag from the prop. A folding prop would cancel that. Plus I don't have to mix gas or have to worry about the prop coming out of the water! ????Barking up the wrong tree! ? Ray Winkle 5275 Knot Home Sarah Creek Gloucester Point, VA. See AOL's top rated recipes and easy ways to stay in shape for winter. See AOL's top rated recipes and easy ways to stay in shape for winter. ________________________________________________________________________ More new features than ever. Check out the new AOL Mail ! - http://webmail.aol.com
