Cal 39 MKII--MKIII displacement

Nov 12, 2014
4
Cal 39 SF
Can anyone help me account for the difference in displacement between these two models? I believe they had identical hulls, ballast, and rigging. The interior, deck and cabin trunk were redesigned for the MK III; but 2000 lbs? That's a frigging lot for a boat that size and I can't even imagine what they could have added that would account for it. And should one then assume that is 2000 lbs less payload that can be carried in the MK III?
 
Mar 20, 2012
3,983
Cal 34-III, MacGregor 25 Salem, Oregon
Can anyone help me account for the difference in displacement between these two models? I believe they had identical hulls, ballast, and rigging. The interior, deck and cabin trunk were redesigned for the MK III; but 2000 lbs? That's a frigging lot for a boat that size and I can't even imagine what they could have added that would account for it. And should one then assume that is 2000 lbs less payload that can be carried in the MK III?
probably a mistake on someones account in supplying the information, either in ballast or actual weight...
but several of the cal boats designed by lapworth had more ballast added in their later versions, but without it being documented somewhere, or an owners manual, how do you know for sure?!!!

here is a link to a cal site with some tech manuals
 
Feb 26, 2004
21,959
Catalina 34 224 Maple Bay, BC, Canada
Sometimes the original weights were somewhat less than what was published, based on skippers actually weighing their boats! Really. While sling scales have been notorious for poor performance, many skippers used better scales and reported at least 1K if not more heavier readings for boats in that size range (like our C34s and the C36s based on reports on those forums).
 
Nov 12, 2014
4
Cal 39 SF
probably a mistake on someones account in supplying the information, either in ballast or actual weight...
but several of the cal boats designed by lapworth had more ballast added in their later versions, but without it being documented somewhere, or an owners manual, how do you know for sure?!!!

here is a link to a cal site with some tech manuals
Except nothing there for any Cal 39s for some reason. I'm pretty sure that if the displacement was underestimated for a 1982 MK II, it was probably similarly underestimated for the 1983 Cal 39 MK III. I think sailboatdata.com generally uses documented numbers and they show the 2000lb difference.
 
Mar 20, 2012
3,983
Cal 34-III, MacGregor 25 Salem, Oregon
Except nothing there for any Cal 39s for some reason. I'm pretty sure that if the displacement was underestimated for a 1982 MK II, it was probably similarly underestimated for the 1983 Cal 39 MK III. I think sailboatdata.com generally uses documented numbers and they show the 2000lb difference.
I have spoken with the guy from sailboatdata on several occaisions (email) about how the information is gathered, and it does not always come from documentation or "fact" sheets... it mostly comes from people who think they know...it may show wrong for a long time, and then when someone has the correct information to offer, and some documentation to back it up, then it will be changed to show what the documentation shows.... and still, the documentation is not always correct..

the guy has a great site and does a good job at getting the stuff listed and does what he can to make sure its correct, but it is mostly community supplied information, and not always perfect the fist time.

if you have anything to share concerning sailboats, they have a member forum similar to this one to share and learn from...:D
 
Nov 12, 2014
4
Cal 39 SF
I have spoken with the guy from sailboatdata on several occaisions (email) about how the information is gathered, and it does not always come from documentation or "fact" sheets... it mostly comes from people who think they know...it may show wrong for a long time, and then when someone has the correct information to offer, and some documentation to back it up, then it will be changed to show what the documentation shows.... and still, the documentation is not always correct..

the guy has a great site and does a good job at getting the stuff listed and does what he can to make sure its correct, but it is mostly community supplied information, and not always perfect the fist time.

if you have anything to share concerning sailboats, they have a member forum similar to this one to share and learn from...:D
Thanks, that's a good reminder. I have seen bits of info change over the years there. But I only cited them because they are widely recognized. The fact is, I've never seen differing numbers cited anywhere. But it's true; there is no way to know for absolutely certain trusting someone else's numbers. I suppose one would have to actually personally weigh several examples of each to be really confident. I should have worded my question as follows: "Assuming for a moment that the displacement figures widely reported for the Cal 39 MK II and MK III (17,000 lbs and 19,000 lbs respectively) are correct, does anyone have ideas about how to account for the extra weight of the MK III (assuming as well that the hull, ballast, and rig are the same)?"