Determination of characteristics

[chris_gee]

I am looking at a boat with the displacement given as 15000 dry and 17000 presumably with tanks filled. Which figure is typically given so that one can compare boat characteristics?
Secondly it comes in cutter or sloop. I would imagine sail area is compared on the basis of 100% foretriangle. The sloop area is 583 with main 302 jib 281. The cutter has the same main but staysail of 134 and a yankee given variously as 374 or 343 totalling 776-810. Is this because the cutter has the mast further aft so the foretriangle is a bit bigger? Even so that doesn't seem to fit because the yankee looked like say 75% of the foretriangle to me.
How does one compare sail area on a cutter v a sloop?
There is no bowsprit so if the mast is in fact moved back one would expect some some increase in foresail size to balance the boat with the same sized main, but then should you really add in the staysail as well as a larger foresail? The combined difference seems a bit high to me. The boat is a Cabot 36 and the figures come from both the original 1970s specs and the new ones since they have started rebuilding them so there is a possibility of a typo or the sailplan having been changed.

[Ilenart]

Originally Posted by chris_gee

I am looking at a boat with the displacement given as 15000 dry and 17000 presumably with tanks filled. Which figure is typically given so that one can compare boat characteristics?

The lesser figure sounds like the "Light" condition ie without crew stores, water or fuel. The heavier No is probably "Half-loaded" with crew. Half-loaded is a better number to use, however the Light number appears to be more commonly quoted in advertising. So long as you are comparing apples with apples it's not a big issue.

I would imagine sail area is compared on the basis of 100% foretriangle.

Its suppose to be, however I have seen lots of Nos quoted that use actual sail area.

The sloop area is 583 with main 302 jib 281. The cutter has the same main but staysail of 134 and a yankee given variously as 374 or 343 totalling 776-810. Is this because the cutter has the mast further aft so the foretriangle is a bit bigger? Even so that doesn't seem to fit because the yankee looked like say 75% of the foretriangle to me.

My guess is they are including the actual size of the sails, so the cutter measurement effectively includes the overlap.

How does one compare sail area on a cutter v a sloop?

Assuming the mast is not moved you effectively have the same area to use irrespective of whether it is a cutter or a sloop. The performance will probably be fairly close. JeffH gives an excelent summary of sloop vs cutter here

There is no bowsprit so if the mast is in fact moved back one would expect some some increase in foresail size to balance the boat with the same sized main, but then should you really add in the staysail as well as a larger foresail? The combined difference seems a bit high to me. The boat is a Cabot 36 and the figures come from both the original 1970s specs and the new ones since they have started rebuilding them so there is a possibility of a typo or the sailplan having been changed.

Not familiar with the Cabot 36. Anyone else help?