Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Rate Thread Display Modes
Old 01-04-2014, 06:47   #226
Registered User
 
oldragbaggers's Avatar

Join Date: Oct 2012
Location: Wherever the boat is
Boat: Cape Dory 33
Posts: 1,019
Re: A Full Keel Blue Water Cruiser Worthy of Living Aboard

Quote:
Originally Posted by Ann T. Cate View Post
I don't know if MPricer is around any more,

Ann
He's probably pricing RVs right about now.
__________________

__________________
Southbound on the ICW

https://share.delorme.com/SVAnteris
oldragbaggers is offline   Reply With Quote
Old 01-04-2014, 07:10   #227
Registered User

Join Date: Mar 2014
Boat: Sovereign 24
Posts: 72
Re: A Full Keel Blue Water Cruiser Worthy of Living Aboard

Quote:
Originally Posted by robert sailor View Post
Polux, If you go back and re read my post I specifically stated "overloading" the light weight boat, that means to add considerably more weight than it was designed to carry. This causes the boat to sink well below its lines which adds considerably to the wetted surface and drag as well as puts higher loads on the rigging. Its not uncommon to see boats in the 30-mid 30 foot range loaded down well beyond what they were designed for and the sailing is effected. Boats in the mid 40's are large enough to carry a typical cruising load from the get go.
Why do you think race boats get stripped of every every additional useless pound onboard?? Quite simply racers know that if you want to go quick you don't do it in an overloaded boat.
I think people are throwing around light weight without understanding what they are saying. Two identical hulls with one being built much lighter, which do you suppose will hold more weight? It's not about weight. It's about hull design (both shape, build quality and bracing) as to what can safely be carried and how it will sit and ride in the water.

I think
__________________

__________________
Phantoms is offline   Reply With Quote
Old 01-04-2014, 07:55   #228
Registered User

Join Date: Mar 2013
Posts: 1,440
Re: A Full Keel Blue Water Cruiser Worthy of Living Aboard

Quote:
Originally Posted by Polux View Post
Regarding that core assumption that modern cruisers are beamier than older ones, it is not only beam but the beam brought aft that increases the waterplan when you load the boat.

When I think about modern mass production beamy cruisers I am thinking about the Oceanis 41 with a beam of 4.20m beam, the Hanse 415 with 4.17m and most of the other 40ft that have about 4.00m.

Perhaps regarding my core basic assumption that modern cruisers are beamier, that you consider wrong, you can tell me of what old heavy beamy boats you are thinking about, I mean the ones with 40fts with 4.00m beam and over. I am not understanding about what boats you refer. By old designed heavy boats I think about the Tayana 42, The Cabo Rico 40, the Passport 40, the Caliber 40 the Morris 40, all with beams around 3.85m, some with less.

New cruising designs are beamier than old ones and they are designed to cruise and to sail with a cruising load. That load, considered boats with the same length, is not less than the one that any old typically narrower cruiser could carry (the one stipulated by the NA).
Old, heavy-designed boats? The boats you reference (most, anyway) are modern designs, not full keels, and the displacements are within 15% of the "newer designed" boats you mention.

You're comparing 40 foot boats with a displacement of 18,000 or 19,000 lbs to boats with a displacement of 21,000 or 22,000 lbs. That's not heavy vs light displacement. (I'd argue that the Cabo Rico, at 26,000 lbs is in a different displacement category.)

My point is that that loading is a factor of displacement, and likely affects the performance as a percentage of overall displacement. It will depend on the design of the specific boat.

I'm sticking with my point that loading is generally a factor of displacement and wetted area, and that a boat that is designed to a heavier displacement can probably sustain more loading-- as it's a percentage factor that's important.

The loading difference between an 18,000 lb boat and a 21,000 boat probably doesn't mean much in terms of a general discussion, as you're within the design parameters of the specific boat.

So I agree with you that the boats you listed are cruising boats and designed for cruising loads. Making a big argument about cruising loads for these boats isn't worth a lot of time.
__________________
letsgetsailing3 is offline   Reply With Quote
Old 01-04-2014, 12:43   #229
Registered User
 
Polux's Avatar

Join Date: Nov 2011
Location: Portugal/Med
Boat: Comet 41s
Posts: 5,748
Re: A Full Keel Blue Water Cruiser Worthy of Living Aboard

Quote:
Originally Posted by robert sailor View Post
Polux is correct when he suggests that a light weight beamier boat will sink less in the water compared to an older heavier displacement narrower boat but the difference is very little.
Keep in mind that when you sink a light weight beamy boat your adding a lot of additional surface area so your best keeping a modern boat as light as practically possible.
The biggest difference between the two is that the heaver boat has a slower motion and doesn't pound going to windward in a larger seaway so for some folks comfort of the heavier boats is very important.
My personal preferences are on the lighter/medium side as these boats tend to sail better in lighter winds which for those that have done a fair amount of offshore sailing know is pretty common, saves on fuel as well.
The downside of many modern boats is that they are designed for dock side or at anchor living because very little thought has gone into the real needs of offshore sailors with proper hand holds, excellent storage and few open spaces to fall across. This of course is very understandable because 99% of the buyers use these boats for day sailing and most spend 95% of their time at the dock. From the manufactures standpoint its a win win because there is a lot less material used to make boats today than in times past. If my memory serves me Island Packet is about the only builder still using full keels
The difference in what regards what a boat sinks with load is proportional to the area of the water plan and it can be big if we compare a boat with a flattish bottom and big beam and a narrower boat with a deep hull.

I agree with you that main market boats are designed taking in account the ones that buy them and accordingly with the more common use sailors give to them. It makes no sense to have them more expensively equipped with items you don't need or use. However they have many extras that are suitable for long range cruising and the manufacturers or the dealers will be happy to prepare the boat for long range cruising (and then it will be a much more expensive boat). Their stability, seaworthiness and sailing performance is in most cases more than adequate for offshore work.

However there are smaller brands specialized in long range cruising boats, even boats for sailing in high latitudes and on those many of the things you need will come standard and all the others you will find in extras.

It is much less expensive to prepare a main mass market boat for offshore sailing than to buy one of those specially prepared voyage boats and that's why most that voyage do that in main market prepared boats.

Regarding sea motion you have for all tastes. Yes the movements of a modern light boat are sharper than the ones of an old narrower heavier boat but on those the movements will have a much bigger amplitude in what regards pitch and roll. The way people responds to those movements is different, there are ones that suffer more with bigger amplitude slow motions others that suffer more with sharper movements with less amplitude. In the end you should chose the boat whose motion you fell more comfortable or if you have not a problem with either, the one that sails better.
Polux is offline   Reply With Quote
Old 01-04-2014, 14:05   #230
Registered User
 
TeddyDiver's Avatar

Join Date: Aug 2010
Location: Arctic Ocean
Boat: Under construction 35' ketch
Posts: 1,826
Images: 2
Re: A Full Keel Blue Water Cruiser Worthy of Living Aboard

Quote:
Originally Posted by Polux View Post
The difference in what regards what a boat sinks with load is proportional to the area of the water plan and it can be big if we compare a boat with a flattish bottom and big beam and a narrower boat with a deep hull.

I agree with you that main market boats are designed taking in account the ones that buy them and accordingly with the more common use sailors give to them. It makes no sense to have them more expensively equipped with items you don't need or use. However they have many extras that are suitable for long range cruising and the manufacturers or the dealers will be happy to prepare the boat for long range cruising (and then it will be a much more expensive boat). Their stability, seaworthiness and sailing performance is in most cases more than adequate for offshore work.

However there are smaller brands specialized in long range cruising boats, even boats for sailing in high latitudes and on those many of the things you need will come standard and all the others you will find in extras.

It is much less expensive to prepare a main mass market boat for offshore sailing than to buy one of those specially prepared voyage boats and that's why most that voyage do that in main market prepared boats.

Regarding sea motion you have for all tastes. Yes the movements of a modern light boat are sharper than the ones of an old narrower heavier boat but on those the movements will have a much bigger amplitude in what regards pitch and roll. The way people responds to those movements is different, there are ones that suffer more with bigger amplitude slow motions others that suffer more with sharper movements with less amplitude. In the end you should chose the boat whose motion you fell more comfortable or if you have not a problem with either, the one that sails better.
Sorry but in some points you are completely wrong.
Increased displacement has much bigger impact to resistance in shallow bodied hull forms than you can imagine by the amount it sinks. One way how NA's and boat designer's predict it is Prismatic Coefficiency if you wan't read what it mean's Understanding the Prismatic Coefficient
Beam doesn't predict roll periods. Google Metacentric Height.

BR Teddy
__________________
TeddyDiver is offline   Reply With Quote
Old 01-04-2014, 15:57   #231
Registered User
 
Polux's Avatar

Join Date: Nov 2011
Location: Portugal/Med
Boat: Comet 41s
Posts: 5,748
Re: A Full Keel Blue Water Cruiser Worthy of Living Aboard

Quote:
Originally Posted by TeddyDiver View Post
Sorry but in some points you are completely wrong.
Increased displacement has much bigger impact to resistance in shallow bodied hull forms than you can imagine by the amount it sinks.
Perhaps you can say what you mean by other words. This does not make any sense to me: "Increased displacement.. has Impact to resistance...by the amount it sinks"????

Quote:
Originally Posted by TeddyDiver View Post
One way how NA's and boat designer's predict it is Prismatic Coefficiency if you wan't read what it mean's
Understanding the Prismatic Coefficient
I know what is the prismatic coefficient but I don't understand why you bring it here. Prismatic Coefficient (Cp) is used to evaluate the volume distribution of the submersed part of the hull ( the hull shape). A high Cp indicates a boat with not fine entries, a low Cp indicates a boat with fine entries.

I guess you want to say Waterplane coefficient (Cw) that is the one that has importance here and measures the the waterplane area ratio towards a rectangle with the same width and length. But this regards only boats with the same beam.

In fact it is much easier than that and given a hull waterplane is easy to calculate how much the boat will sink with a given load. Archimedes discovered that thousands of years ago: you have just to calculate the volume of the boat at the waterline correspondent to the volume water displaced that equals the load weight. As the volume is found multiplying the area of the waterplane by the height of immersion it is easy to understand that the important factor is beam and the waterplane coefficient.

Quote:
Originally Posted by TeddyDiver View Post
Beam doesn't predict roll periods. Google Metacentric Height.
BR Teddy
Who said that beam predict roll periods? I did not even talked about roll periods. what I said, and it is pretty evident, is that beam diminishes roll. The initial stability on a hull is almost all generated by beam. The beamier the hull, the bigger the initial stability and less roll it will have in waves. Think on a big catamaran and compare it with a narrow boat in what regards roll and you will understand the picture.
Polux is offline   Reply With Quote
Old 01-04-2014, 19:10   #232
Registered User

Join Date: May 2012
Location: Texas
Boat: Pearsnon, 422, 42 feet
Posts: 40
Re: A Full Keel Blue Water Cruiser Worthy of Living Aboard

Quote:
Originally Posted by oldragbaggers View Post
He's probably pricing RVs right about now.
I'm still here....I have to admit, much of what is being posted now is way more detailed into the design and physics of boat building than I ever wanted to get into. However, I do appreciate the time and energy the IP's expend in helping to develop this picture.
__________________
Mpricer is offline   Reply With Quote
Old 01-04-2014, 19:13   #233
Registered User

Join Date: May 2012
Location: Texas
Boat: Pearsnon, 422, 42 feet
Posts: 40
Re: A Full Keel Blue Water Cruiser Worthy of Living Aboard

Quote:
Originally Posted by Ann T. Cate View Post
I don't know if MPricer is around any more, but, thinking back to my experiences sailing a Herreshoff Mobjack with friends on the first weekend in March, this is a boat he might actually like, and not be bothered by its lack of maneuverability.

It's a 45 ft. ketch, and with lovely accommodations. There are two in this area at this time, of which I am aware.

Ann
Hey, this is the OP I'm still here.
__________________
Mpricer is offline   Reply With Quote
Old 01-04-2014, 19:52   #234
Registered User
 
Polux's Avatar

Join Date: Nov 2011
Location: Portugal/Med
Boat: Comet 41s
Posts: 5,748
Re: A Full Keel Blue Water Cruiser Worthy of Living Aboard

Quote:
Originally Posted by Mpricer View Post
Hey, this is the OP I'm still here.
Talking in a more plain language :-), this was the best suggestion so far:

Quote:
Originally Posted by The cockpit kid View Post
Why not try doing a charter boat hire ,and maybe join a sailing club for a while that way u get to go out on other folks boats ,get to pick there brains, most any body who owns a boat would be happy to show off there pride and joy and be more honest in there opinions of how their boat handles , I spent about a year and a half doing that before buying my own boat ,and along the way meet some really. Nice people.
And in the end was extremely happy with my purchase,which incidentally was through word of mouth (saving brokerage fees)
if the worst comes to the worst and you buy a boat at the right price and are not happy about it you can then move it on and not be to much out of pocket for your next purchase
Good luck with your search
John norman
I have done the same regarding chartering and test sailing boats to know exactly what I wanted not during one year and a half but during several years, 4 or 5 I guess, with many boats tested and charted and I had already had owned some boats previously so I new already approximately what I wanted.

The type of boat I have chosen it will not be almost for sure the one you will want and it is probable that your choice would not be the choice that John have made. There are so many different types of boats and so many different types of sailors (and in what regards that sailing experience counts too) that it is better if you make your own choice instead of choosing one among the many suggestions that are being offered to you. They are very different and only one would be the right one for you even if they are right for somebody else.

I suggest you draw a budget and inside that budget start to charter very different types of boats, full keel, medium and light modern boat. Chose some nice places to charter them and have fun while you are learning what suits you best. when you decide what type you favor, then narrow the choice on that type.
Polux is offline   Reply With Quote
Old 01-04-2014, 22:46   #235
Registered User
 
TeddyDiver's Avatar

Join Date: Aug 2010
Location: Arctic Ocean
Boat: Under construction 35' ketch
Posts: 1,826
Images: 2
Re: A Full Keel Blue Water Cruiser Worthy of Living Aboard

Quote:
Originally Posted by Polux View Post
Perhaps you can say what you mean by other words.

It's complicated and I don't have the time now..

I know what is the prismatic coefficient but I don't understand why you bring it here.

Becouse it's the most accurate method to predict hulls wave making resistance

I guess you want to say Waterplane coefficient (Cw) that is the one that has importance here and measures the the waterplane area ratio towards a rectangle with the same width and length. But this regards only boats with the same beam.

No it hasn't..

In fact it is much easier than that and given a hull waterplane is easy to calculate how much the boat will sink with a given load. Archimedes discovered that thousands of years ago: you have just to calculate the volume of the boat at the waterline correspondent to the volume water displaced that equals the load weight. As the volume is found multiplying the area of the waterplane by the height of immersion it is easy to understand that the important factor is beam and the waterplane coefficient.

Easy, yes, but doesn't tell a s#% about resistance

Who said that beam predict roll periods? I did not even talked about roll periods. what I said, and it is pretty evident.

You did!

"Yes the movements of a modern light boat are sharper than the ones of an old narrower heavier boat but on those the movements will have a much bigger amplitude in what regards pitch and roll"
Answers Green
I'm not trying to argue here but got to state the facts when they are overlooked. Have a nice day

BR Teddy
__________________
TeddyDiver is offline   Reply With Quote
Old 02-04-2014, 00:49   #236
Moderator
 
carstenb's Avatar

Cruisers Forum Supporter

Join Date: May 2012
Location: Copenhagen
Boat: Jeanneau Sun Fast 40.3
Posts: 4,936
Images: 1
Re: A Full Keel Blue Water Cruiser Worthy of Living Aboard

Quote:
Originally Posted by Mpricer View Post
I'm still here....I have to admit, much of what is being posted now is way more detailed into the design and physics of boat building than I ever wanted to get into. However, I do appreciate the time and energy the IP's expend in helping to develop this picture.
Well, now that you are throughly confused......................

Here's a suggestion. Drive down to your local marina and walk around. Spot a couple fo well-maintained boats in the approximate size you're looking, say 2 heavy displacement boats, 2 modern boats.

Drop a note to the owners asking if they will take you for a day sail (offer them a couple of bottles of champagne - sailors are easy marks for a bottle of bubbly)

By day sail I also mean 4-6 hours. Talk to each of them - how heavy weather have they been out in? positives and negatives of their boat etc etc.

This will take a few weekends - but you will be much wiser at the end of it.

Or as another poster suggested - drop it and start pricing RVs
__________________
I spent most of my money on Booze, Broads and Boats. The rest I wasted - Elmore Leonard
carstenb is offline   Reply With Quote
Old 02-04-2014, 09:03   #237
Registered User
 
Polux's Avatar

Join Date: Nov 2011
Location: Portugal/Med
Boat: Comet 41s
Posts: 5,748
Re: A Full Keel Blue Water Cruiser Worthy of Living Aboard

Quote:
Originally Posted by TeddyDiver View Post
Answers Easy, yes, but doesn't tell a s#% about resistanceGreen
I'm not trying to argue here but got to state the facts when they are
overlooked. Have a nice day

BR Teddy
So you are agreeing that a narrower boats sinks more on its line than a beamier boat for a given load but say that a narrow boat has a bigger "resistance" to sinking????

This is not a prediction:

"Yes the movements of a modern light boat are sharper than the ones of an old narrower heavier boat but on those the movements will have a much bigger amplitude in what regards pitch and roll"

It is a well known fact at least for typical boats, I mean modern light beamy boat compared with heavy narrower old designs.
Polux is offline   Reply With Quote
Old 02-04-2014, 09:18   #238
Registered User
 
DDabs's Avatar

Join Date: Aug 2011
Location: St. George's, Grenada
Boat: Caliber 40LRC
Posts: 1,505
Images: 16
Re: A Full Keel Blue Water Cruiser Worthy of Living Aboard

this thread is like watching an interesting documentary, but then it just keeps going and going and now i'm not sure what's even happening anymore and i think i'll just turn the tv off
__________________
DDabs is offline   Reply With Quote
Old 02-04-2014, 10:30   #239
Registered User
 
TeddyDiver's Avatar

Join Date: Aug 2010
Location: Arctic Ocean
Boat: Under construction 35' ketch
Posts: 1,826
Images: 2
Re: A Full Keel Blue Water Cruiser Worthy of Living Aboard

Quote:
Originally Posted by Polux View Post
So you are agreeing that a narrower boats sinks more on its line than a beamier boat for a given load but say that a narrow boat has a bigger "resistance" to sinking????

This is not a prediction:

"Yes the movements of a modern light boat are sharper than the ones of an old narrower heavier boat but on those the movements will have a much bigger amplitude in what regards pitch and roll"

It is a well known fact at least for typical boats, I mean modern light beamy boat companred with heavy narrower old designs.
Yes and no. Yes that narrower boat with smaller waterplane area sinks more. However this has nothing to do with wave making resistance which is predicted by Cp.
Well known 'facts' are sometimes just hearsay. Beam doesn't correlate directly to 'amplitude' ie roll period. It's more related to vertical distribution of mass.
BR Teddy
__________________
TeddyDiver is offline   Reply With Quote
Old 02-04-2014, 14:30   #240
Registered User
 
Polux's Avatar

Join Date: Nov 2011
Location: Portugal/Med
Boat: Comet 41s
Posts: 5,748
Re: A Full Keel Blue Water Cruiser Worthy of Living Aboard

Quote:
Originally Posted by TeddyDiver View Post
Yes and no. Yes that narrower boat with smaller waterplane area sinks more. However this has nothing to do with wave making resistance which is predicted by Cp.
Well known 'facts' are sometimes just hearsay. Beam doesn't correlate directly to 'amplitude' ie roll period. It's more related to vertical distribution of mass.
BR Teddy
I give up! Last post on this. What stops roll movements and prevents them to happen is initial stability. Most initial stability comes from hull form stability. Hull form stability increases exponentially with beam.
__________________

Polux is offline   Reply With Quote
Reply

Tags
cruise, cruiser, keel, living aboard, water

Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Hunter 27' : blue water/carrib island hopping worthy? Capt Darren Monohull Sailboats 14 18-08-2016 13:39
Morgan 27 blue water worthy? Sqelix Monohull Sailboats 10 04-01-2013 11:21
Looking for - Blue Water 40+ft - $60k Full Keel camcam Monohull Sailboats 17 14-08-2012 19:07
Sea-worthy 30 footers for live-aboard? tetraj Monohull Sailboats 7 27-07-2012 20:10
I'd like to get your thoughts on some full keel blue water cruisers Miu Miu Monohull Sailboats 21 15-06-2012 17:53



Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 03:37.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.