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Southern Cross 31?

49K views 40 replies 15 participants last post by  sailingfool 
#1 ·
Im in the market for a 30 something, blue waterish boat and recently become enamored with the Southern Cross 31. I have been searching the net (and SailNet) consistently with not very much information found, even on the owners site

Its numbers make it off shore worthy, but the sail area - displacement ratio of 12.55 makes me thinks its REALLY pokey, much like Westsail..

Thoughts?

Is there a fin keel/skeg rudder boat that has better performance numbers but a capsize ratio well under 2? (Souther Cross is 1.55) or are the numbers diametrically opposed?

We have considered a Bristol 29.9, and Bayfield 29

thanks in advance

Dave in NC
 
#2 ·
Dave,

I'm surprised that the SA/D ratio is so low on the Southern Cross 31. That doesn't sound right to me, but I have no first hand knowledge. Might be worth a double check. Is this not the Gillmer 31, built by Ryder? If so, there should be some discussion in Ferenc Mate's "Best Boats to Build or Buy".

You asked: <<Is there a fin keel/skeg rudder boat that has better performance numbers but a capsize ratio well under 2? (Souther Cross is 1.55) or are the numbers diametrically opposed?>>

I will shamelessly put in a plug for our boat model, the Pacific Seacraft Crealock 31 (not to be confused with the PSC Mariah 31). It has the attributes you describe, in the size range you are looking at.
 
#5 ·
Windrose2 - $78k is out of my range Dave, but thanks.

JohnR - got the figures from the Carls SailCalc.. in pics is sure does look like the main is small, but maybe they are not counting the headsail?? dontknow

Gburton - I too heard of the cored hull.. but dont really know what to make of it. Anything designed with a 13000+ of displacement in 30 ft of boat has got to be solid, no? Is your concern about water penetration or strength if struck by something?

Im not concerned about the ruggedness, but more about light air and pointing ability.. the figures I reference are really low..

The only owners site that Im aware of is www dot southerncross-boats dot org/
and it doesnt have specs
 
#6 ·
With a sail area to displ of 12.5 I would think a Westsail would sail circles around them :)

Have you looked at a Niagara 35 ? They have a long fin keel and a skeg rudder and were designed for blue water. There are a lot of them on the Great Lakes in really nice shape.

I would be concerned about the wooden bow sprint on the Bayfiled as this is were the forestay attaches. Even though they have a traditional look and are good boats I am not so sure they were ever intended for off shore work.

Good Luck
Gary
 
#7 ·
Dave in NC,

Carl's sail calculator is a neat tool, but I have seen errors there. Not output errors, but input errors. My understanding is that anyone can load up the specs to a boat model and run the numbers through the calculator. Sometimes the numbers come from dubious sources (like the specs listed in Yachtworld) and to the best of my knowledge there is no process in place to verify.

Then again, maybe those numbers for the SC 31 are spot on. If you're truly interested in this model, it would be worth doing some homework to verify the specs.
 
#8 ·
The Southern Cross 31 is a pretty solid boat, with circumnavigations to its credit. While it has a cored hull, the hull is very solid, provided it hasn't had any water penetrate the core.

BTW, from my calculations, the SA/D should be more like 13.25 or so, rather than the 12.55. I am basing this on the following specifications:

LOA 31', LWL 25', Beam 9.5', Displacement 13600, SA (Main + 100% Jib) 472 sq. ft. The main and 100% Jib areas were calculated based on the I, J, P, and E measurements of the boat, which are 36.5, 15.5, 31, and 12.2 respectively. Mainsail area is approximately (P*E)/2 or (31*12.2)/2 or 189.1 sq. ft. 100% Jib are is approximately (I * J)/2 or (36.5 * 15.5)/2 or 282.9 sq. ft.

These numbers are probably a bit conservative, since they assume a mainsail with no roach area whatsoever, which is somewhat unusual today. BTW, the numbers for the SC31 are from the sail specifications section of the MauriProSailing website. The displacement, LOA, LWL and Beam are from several different sites, which all had them listed the same.
 
#9 ·
Correct me if I'm wrong, but aren't many of the Southern Cross 31's owner-finished? That would be my biggest concern if I were looking at them as a bluewater yacht. Aesthetically and on paper, I really like the SC31.

If I were shopping an SC31, I'd also consider some of the following vessels:

Westsail 32, PSC 31, IP 31, Baba 30, Valiant 32, Willard 8 Ton
 
#10 ·
Yes, many of the Southern Crosses were owner finished, being sold as bare hulls IIRC. Some of the ones I've seen were quite well done—better than the factory finished ones in some cases—others were miserable.
 
#12 ·
Saildog - wow - Im impressed! - thats more information than Ive been able to find..Ive got emails out to every SCowner.org addr I can find!

SA/Dsp ratio - wouldnt the calculation cover how much sail you can hang in the I,J,P & E triangles and hence a cutter rig would have advantages?

Kwaltersmi - thanks for the other suggestions.. pricing wize, for some reason, the SC's Ive seen seem to fall below $40k, even $30k while the others you suggest, in decent shape generally start above $50k

maybe the "owner finished" issue is why there is a strong following on the net..
 
#13 ·
I don't know about how the SA/D is calculated for a Cutter-rigged boat, since I don't deal with them all that much. However, as I said, the numbers I gave you are probably a bit on the low side, since most mainsails are cut with some roach to them, especially if they have any battens in the sail.

The PSC 31, HR Monsun and Mistral, Westsail 32, are other boats you could look at. The HR Mistral will probably perform much better than the PSC31 and WS32, since they're fin keeled IIRC. The Monsun is a full-keel design.
 
#14 ·
Traditionally, for the purposes of calculating SA/D, cutters are calculated like sloops, in other words using 100% foretriangle.

That said I have seen calcs that use 100% fore triangle plus 100% size of the staysail for the published sail area and I understand that Island Packets SA/D is calculated using the area of a genoa. For the purpose of SA/D and center of effort calcs, sails are always calculated as straight edged, ignoring roach or hollow.

Jeff
 
#15 ·
Thanks Jeff... Good to know. :D
 
#16 · (Edited)
SailingDog said: <<The PSC 31, HR Monsun and Mistral, Westsail 32, are other boats you could look at. The HR Mistral will probably perform much better than the PSC31 and WS32, since they're fin keeled IIRC. >>

It's not entirely clear, but I assume you meant that only the HR Mistral was fin keeled? As a point of clarification, the boat normally referred to as the "PSC 31" is fin keeled also. Confusion sometimes arises because PSC had an earlier model called the Mariah 31 (designed by Morschladt) that indeed was full-keeled and is very similar to the Westsail 32 in appearance. Probably in performance too.

The PSC 31, designed by Crealock, has a 4'10" fin, or optional shoal draft with a 4' Scheel keel fin variant. This boat is distinguished from its otherwise very similar canoe-sterned stable mates by its traditional wine-glass transom.

Edit: To further clarify, here are some photos of a PSC 31:

http://www.yachtworld.com/core/list...1177436514000&photo_name=Photo+1&photo=1&url=

http://www.yachtworld.com/core/list...o_revised_date=1177436680000&photo_name=Stern

And here is a Mariah 31, also built by PSC:

http://www.yachtworld.com/core/list...ariah&photo_revised_date=1&photo_name=Photo+2

http://www.yachtworld.com/core/list...1168377472000&photo_name=Photo+1&photo=1&url=

The Mariah is more in keeping with the SC31/Westsail 32, etc, but the OP did enquire about fin-keeled boats so I mentioned the PSC 31.

Jeff is correct, the SA/D is supposed to be calculated without the staysail area for baseline apples-to-apples comparison (and I've heard that IPs numbers include the staysail too). Still, it doesn't hurt to also run the calculation with the staysail area included to better understand how the boat might perform under certain conditions. We mostly use our staysail when reaching in light air, when the extra area is most advantageous.
 
#17 ·
John-

You're correct...I often confuse the PSC31 and the Mariah, since they're both 31' boats... :D The Mistral is fin-keeled, as is the PSC 31. Does the PSC31 have a spade rudder or is it skeg-hung? The one on the Mistral is skeg hung IIRC.
 
#18 ·
I couldn't pass this one up :) Although i am a bit biased! I "fell in love" with mine last fall for 10k and spent all winter/spring/summer working on it. I had my 4th and best sail last week hitting 6.9knts upwind.....i have no idea why people say these boats are slow. They need speed to tack and dead downwind is a bit rolly but they sail VERY well. I mean it's not going to keep up with G or SD :) but i really like it. I put the staysail and headsail on rollers so it is very easy to singlehand. They are actually quite manuverable with the huge rudder hanging off the back. I am docked on a small (20' wide) tidal river with strong currents but i can still turn 360 deg. For the money you can't touch a better bluewater boat! I reaserched this issue heavily! The Bayfields, IP's, Baba's are way more $ and not as strong. The Westsail is too slow and heavy (but bigger inside). I'm headed out tommorrow....12-17knts with gusts too 25...yeah!!! I really like the versatility of the sailplan (even on such a small boat). Don't let everyone scare you about the airex...it is Tough stuff. I replaced all my thru-hulls and scraped out the core around them. It was nearly impossible to remove....very strong...even where some water had entered. The BIGGEST issue is the cored area of the deck under the deck stepped mast...it is plywood and there is not enough of a crown for the water to run off, so it seeps in through the mast step bolt and radio wire holes. Mine was 100% wet so i cut it off and re-cored it. It was not very hard (i still can't find reason to justify the cost of repair at most boatyards). Of course most boats have cored decks so it's a common issue. I love my SC.....it is everything i was looking for. Sails well, tracks well, easy to handle alone and very rugged ( i have to keep my kids safe :) ).
 
#19 ·
SailingDog,

Yes, it's a common mistake. That's what happens when a builder makes two completely different models of the same length, even if not at the same time. Perpetual mistaken identity.

Yes, the rudder is skeg hung, with the propeller in an aperture -- not the best for backing down, but well protected from pot warps (we pay them little heed and often sail right over them).

SC31,

Sounds like you got a great deal on a solid boat, even if it needed some work. Enjoy the breeze!
 
#20 ·
SC31-

Just curious...but how do you turn a 31' boat in a 20' wide river... I'd really love to learn how to do that... then maybe I could fit a 18' wide boat in a 13' wide slip. :D

For the money, the SC's are probably some of the best boats for the buck for a bluewater capable boat.
 
#22 ·
That does sound a bit optimistic doesn't it ;) Sorry...my kids are shouting at me in the background. It opens up to about 50-60 ft to turn around. But the docks are perpendicular to the current and there is only about 20-30 ft to back out. I've been hanging out with the yard guys all year and at the end of the day they sit and drink beer for an hour and watch everone's mistakes....laugh about people finding new rocks to hit at low tide. I was so paranoid because i had heard such bad things about how the prop/rudder/keel setup of the SC would be horrible. It is actually very easy to manuver. I have a new F-16 anchor on the bowsprit and all i could imagine was twisting up someones rigging etc... :( After my last sail though, i set the boat right on the dock in a 1.5knt current and stepped down casually with both lines in my hand, tied her up and killed the motor. They were all sitting there drinking, watching but in usual new england demeanor they said not a word....they only comment on the mistakes :)
 
#23 ·
LOL... a little optimistic, and a bit unrealistic... ;) 50–60' makes more sense. :D
 
#24 ·
southerncross - thanks for the post - maybe you (or anyone else) can answer my question #254: after length & draft, I had on my list: a keel stepped mast as a requirement for blue water capability.. then i stumbled over the SC31! What gives? Why wouldnt a CE Ryder build without? Seems like a no brainer

btw, I just rec'd in the mail John Vigors "Twenty Small Sailboats to Take You Anywhere" and it has a chapter on the SC31.. he comments about the cored hull (he summizes its not his 1st choice) and gives the boat the following ratings:
Seaworthyness: 7 (out of 10) - surprising for a boat that gets a 1.55 capsize ratio!
Speed rating: "No sluggard"
Ocean Comfort level: 2 persons, maybe 3 max

Overall, I think he likes the boat, but questions the lack of a keel stepped mast as well..

Dave in NC
 
#25 ·
DB-

There are many bluewater capable boats that have deck-stepped masts. The preference of a deck-stepped or keel-stepped mast is mostly personal at this point. What makes you think a deck-stepped mast is less seaworthy than a keel-stepped mast??
 
#26 ·
Dave,

One thing you need to realize is that the capsize screen ratio (or the motion comfort index) tells you absolutely nothing about how likely a boat is to capsize or how comfortable its motion is likely to be. I know that I have explained this on this forum before but here it is again, both of the capsize screen formula and motion comfort index formulas were developed at a time when boats were a lot more similar to each other than they are today. These formulas have limited utility in comparing boats that are very similar but are totally useless and misleading in most cases.

Neither formula contains almost any of the real factors that control motion comfort or stability. Neither formula contains such factors as the vertical center of gravity or buoyancy, neither contains weight or buoyancy distribution, and neither contains any data on dampening. In other words these formulas lack all of the major factors that actually control motion comfort or likelihood of capsize. Weight in and of itself has next to no bearing on motion comfort or stability; nor does max beam, which in this formula is measured at a single point on the deck.

An example that illustrates this might be two boats of equal length, equal max beam, and displacement, but one had a longer waterline and a 1000 lbs of lead in a deep draft keel, while the other had a shallow draft keel with a 1000 lbs less ballast, a hard turn of the bilge, and a 1000 lb heavier interior and deck.

Obviously the boat with the deeper draft, lower ballast and longer waterline would be the less likely to capsize and offer a slower motion through a smaller roll angle, yet their capsize ratio and motion comfort index would be identical.

That is why I see these formulas as being worse than useless.


Jeff
 
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