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  #11  
Old 12-10-2011
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That's very interesting information about the large windows and confirms something that has been nagging me. With all the negative things I've read concerning large windows at sea, I've often thought that surely the designers and engineers would have considered their impact (or impact resistance) as well.

Having my mind set on a certain keel shape is actually something I'm trying to avoid and the keel is only one part of the overall boat. It was mentioned earlier that having a kindly motion is desireable. What about the shape of the bow and stern? Overhangs? What actually contributes to that kind motion? It's not my intention to focus only on the keel. What's your thoughts on displacement? In all reality, do the moderate to heavy displacement boats lend themselves better to cruising because of the amount of stores and personal items cruisers carry?

Also, what is your take on cockpit size? They seem to vary greatly in size and, at least to my eye, volume. I would think that modern cockpits could be engineered to drain water quickly. In fact, some of the walkthrough transoms I've seen look like they could actually spit the water out.
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  #12  
Old 12-10-2011
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I thin you still need to be careful about big windows since you need to consider what market the boat is being needed for. Having said that, technology does continually advance and the correct advice from 20+ years ago may not be correct now.

Other than some obvious facts like a longer waterline means you can go faster, I think the average sailor (and certainly me) can say what shape hull is best and how much overhands you should have. I think it makes sense to consider boats in their totality and in particular their reasoned reputation.

Not sure if you know this website, Sail Calculator Pro v3.53 - 2500+ boats. It has data on most boats and will tell you something about load carrying capacity and comfort (although the comfort ratio has been often criticized. In the data below, I compared my boat to a Beneteau Oceanis 44 centercockpit which is one of the Beneteaus cruising line. Some interesting comparisons including the fact that the Beneteau which is much lighter needs more weight added to it to sink an inch (because its cross-sectional waterlne area is larger). Note that this says nothing about the impact of load on sailing ability and stability. Also note that the comfort ratios and capsize ratios are entirely different. So even though these are two mid-40s cruising boats, they are very different.


LOA Beneteau Oceanis 44 CC
* * 42.12
Bristol 45.5
* *46.39
LWL Beneteau Oceanis 44 CC
* * 36.54
Bristol 45.5
* *37.45
Beam Beneteau Oceanis 44 CC
* * 13.9
Bristol 45.5
* *13.27
Displacement Beneteau Oceanis 44 CC
* * 20544
Bristol 45.5
* *35214
Sail Area Beneteau Oceanis 44 CC
* * 821
Bristol 45.5
* *968
Capsize Ratio Beneteau Oceanis 44 CC
* * 2.03
Bristol 45.5
* *1.62
Hull Speed Beneteau Oceanis 44 CC
* * 8.1
Bristol 45.5
* *8.2
Sail Area to Displacement Beneteau Oceanis 44 CC
* * 17.51
Bristol 45.5
* *14.42
Displacement to LWL Beneteau Oceanis 44 CC
* * 188
Bristol 45.5
* *299
LWL to Beam Beneteau Oceanis 44 CC
* * 2.63
Bristol 45.5
* *2.82
Motion Comfort Beneteau Oceanis 44 CC
* * 24.75
Bristol 45.5
* *42.97
Pounds/Inch Beneteau Oceanis 44 CC
* * 1815
Bristol 45.5
* *1776
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  #13  
Old 12-10-2011
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SailCalc's capsize ratio is almost meaningless as well as comfort ratio as stated above. It is a formula only using beam and displacement. The heavier boat wins regardless of where the weight is.
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  #14  
Old 12-10-2011
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Quote:
Originally Posted by Dean101 View Post
Extended Cruising - Crosses oceans. In many cases ports of call may include destinations where repair facilities and moorage may not be available, anchoring only. Long periods at sea where forecasting may be spotty/unreliable at times. Typical crossings are on well travelled routes with ocassional deviations and planned for relaxation and enjoyment. Rescue may take a while depending on location. Must be self-sufficient.
1. Versatile sail plan with strong rig
2. Reliable self-steering
3. Rugged hull
4. Plenty of tankage (water, fuel, etc.)
5. Storage space for stores and spares
6. Good ground tackle.
7. Kindly motion in a seaway.
Thor Heyerdahl did this on a raft, when he sailed from Peru to Tahiti on the Kon Tiki.

While I have grander plans for my get away in a few years, and stories like this are always the exception to any rule, I've often wondered about the lists of essential equipment people say are needed. That's not a criticism of the list you have - but mostly of blue water sailing books I read that look like an ad supplement for marine stores :-)

Last edited by joelsanda; 12-10-2011 at 05:29 PM.
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  #15  
Old 12-11-2011
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Killarney, I checked out the website you suggested. Very handy to be able to compare boats quickly. I completely agree with you about the need to take the entire boat into consideration and I've been trying to do just that as I research boats. The criteria I've been using so far as pass/fail qualifier for entry onto my short list of choices are;

Length 32' to 40' with 36' being ideal, full or fin keel, cockpit not overly large, companionway raised to keep out water, small opening ports, no large windows, main sheet not obstructing cockpit, 6' 2" min. headroom, decent galley preferably L or U shaped, must have nav station, good reviews, and generally available under $40k - $50k.

I didn't mention a rig and although I'm thinking a cutter sounds like the best choice, I'm flexible on that. I'll be living aboard, initially coastal cruising the eastern U.S. and throughout the Carribean. A trip to Europe and the Scandinavian countries then it's off to the Pacific. I want to visit S. America and cruise the coastline up to the Aleutian chain, visit Asia and the south Pacific.

So yes, looking at the overall boat is important but I need to understand what I'm looking at so I can make an informed decision as to whether what I'm looking at will keep me safe and comfortable while doing all that.

@ Mitiempo - Until I checked out Killarney's suggested site I've been using cruisingresources.com to look up ratios and factors. Are there any other sites you can suggest? I'm not really clear on what information is needed to breed accuracy into these numbers and I take them all as a general assessment rather than difinitive information.

@ Joelsandra - Feel free to criticize away. I'm beginning to think that maybe I'm going at this the wrong way with the list idea. I agree with you about the books and some of the equipment people say you need. My intent with this thread was not to create yet another list of electronics or spares needed for offshore trips but rather to gain some knowledge as to what makes a boat the right choice for its intended use. We hear things like a comfortable motion, windward abilities, and stability. I want to know what makes a boat have those things because, frankly, I don't want to take the sellers word for it.

People write about a boat being slow but never say what they're comparing it to. When someone says a boat lacks windward abilities, does that mean it can't point higher than 45 degrees off the wind? How high does a cruising sailboat need to point? Sometimes I think that racing plays a big factor in what people think about cruising boats. I think that for some people performance is the sum of speed, maneuverability, and pointing high. My opinion is that performance is the ability of the boat to do what it was intended to do. By that standard, if I want the boat to carry a lot of weight, have plenty of storage, get me around the world safely, and be able to come through a gale smelling like a rose, then a Westsail 32 is a high performance boat! Now let's see what kind of reaction that particular statement will inspire!

You can't really blame the marine outlets since that's what they are in the business of doing, or even the people making the lists since those things are what they feel comfortable with. Even proponents of a certain type of rig are expressing their personal choice. What works for one may not work for another. Slocum changed his rig more times than some people change their underwear, so where does that leave us?
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  #16  
Old 12-11-2011
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As was pointed out, that website only uses calculations based on generally available data like LWL, Displacement, 100% fore triangle sail area, etc. I would disagree that it is "almost meaningless". More accurate measurements can be obtained empirically but those are not available for most boats so something (an approximation) is better than nothing.

About boat speed, it is not entirely a relative thing. You can get a PHRF rating for many, many boats and that will tell you something (far from everything). Short of really top-level racing which has become quite quantitative in its approach is a largely qualitative endeavor. As to speed, it is better to go fast than slow if it can be done in comparable comfort and safety. It takes all types though. We met a couple cruising on a J40 and then did Norfolk to BVI in 8 days when it was really honking. This is a good thing since you take less of a beating and have more time where you are going. We met a man in Fiji who was cruising on an old Pearson 36 and only used a 90% headsail (no matter the conditions - and I don't mean with the main - he only used the jib). For his planning he used 50 miles a day for planning purposes in the trades - we use 120 and rarely would be less than 100 and can do in the 160s and 170s fairly often. His comment is that he has lots of food and water on board along with lots of books so he doesn't care how fast he goes. As I said, all kinds.
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Back to Grenada in early December. Not sure I will remember how to sail. Will spend the winter and early spring in the Caribbean and then head to Bermuda and the northeast US. Still trying to decide if we will bring the boat to Canada, either in 2015 or 2016.
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  #17  
Old 12-11-2011
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Killarney

Capsize ratio is based on 2 numbers only - beam and displacement. If you take a boat - any boat - and add 1000 lbs to its deck, mast, or cabin table it has a much better capsize ratio. How can that not be meaningless?

Here's the best link I have seen for all ratios pertaining to stability, hull speed, D/L ratio and others. Capsize Formula It is the US Sailing site.

For many of these calculations to be used properly you have to know how they are derived. D/L ratio is another suspect ratio when used to compare boats of different types - many think a low D/L ratio means a light boat but not really.
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  #18  
Old 12-12-2011
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I said these were approximations and not exact indicators

Quote:
Originally Posted by mitiempo View Post
Killarney

Capsize ratio is based on 2 numbers only - beam and displacement. If you take a boat - any boat - and add 1000 lbs to its deck, mast, or cabin table it has a much better capsize ratio. How can that not be meaningless?

Here's the best link I have seen for all ratios pertaining to stability, hull speed, D/L ratio and others. Capsize Formula It is the US Sailing site.

For many of these calculations to be used properly you have to know how they are derived. D/L ratio is another suspect ratio when used to compare boats of different types - many think a low D/L ratio means a light boat but not really.
I understand the derivation (and meaning) of these values as I used to teach math. For your comments about Capsize Ratio, there are some interesting comments about the vertical position of the center of gravity to the left of the formula calculating box on the US sailing site that suggest that this is a relatively unimportant value in preventing capsize but or more significance in recovering from capsize once it happens. In any case it is a useful measure when nothing more is available.

The D/L ratio again is only a start and the value is affected both by displacement and waterline length - I have never seen what this ratio would be for one of the old (think it was) Universal Rule boats that had incredible overhangs. On my Bristol the LWL is relatively short but once you actually start moving the stern squats and you gain probably 18 inches of waterline. When someone looks at this ratio, it does not matter very much if one boat is 290 and another 270, but if one is 290 and another is 200 it does indicate something different.
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Back to Grenada in early December. Not sure I will remember how to sail. Will spend the winter and early spring in the Caribbean and then head to Bermuda and the northeast US. Still trying to decide if we will bring the boat to Canada, either in 2015 or 2016.
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  #19  
Old 12-12-2011
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Yes, if one boat is 200 D/L and another 290 D/L there is a difference - the one at 200, assuming the same overall length, could well be heavier.

One of the examples of the capsize ratio being totally ineffective is the Pogo 10.50.
7937 lbs displacement
2425 lbs ballast (31%)
Ballast on the bottom of a 9' foil - about as low as it can get on a boat 35'
long.
The capsize ratio for the Pogo is 2.57
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  #20  
Old 12-12-2011
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And if I am considering a Pogo 1050 for extended cruising I will remember this. The OP was asking about boats of a more conventional type and not ones like this that would useless for extended cruising.

Hopefully more helpful advice - the prevailing wisdom on Oz (heard independently from several people with extensive cruising backgrounds) is that black bottom paint attracts (amorous?) whales. Can't comment personally since I am a blue paint kind of guy.
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Back to Grenada in early December. Not sure I will remember how to sail. Will spend the winter and early spring in the Caribbean and then head to Bermuda and the northeast US. Still trying to decide if we will bring the boat to Canada, either in 2015 or 2016.

Last edited by killarney_sailor; 12-12-2011 at 07:20 PM.
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