Results 1 to 39 of 39

Thread: A Leeboard Question

  1. #1
    Join Date
    Nov 2007
    Location
    cambs
    Posts
    1,549

    Default A Leeboard Question

    As a total non sailor (at present), I have been reading all the sailing threads and think I have found out that lee boards are wing section shaped to give lift to counter the push of the wind. On their website, the S-D pivoting leeboard is described as a hydrofoil shape (I presume that to be a wing section) - yet the write up says you can leave it in position on the windward side. My logic says that this would then be giving lift in the wrong direction........ so I need someone to point out where my thoughts are going wrong: Does the lee board give lift to counter the leeward drift? (I think that means it will be trying to move the boat towards the wind to balance the sideways force of wind) in which case, why can a pivoting lee board be left in the water when on the windward side when the lift will be exaggerating the leeward drift?

    I'm interested in this because my current project is repairing and refurbishing an old PBK type canvas on frame canoe to sail.(Its a kayak really but back when it was designed it would have been called a canoe so no more comments about that please!)
    I want to do everything in the original style, and the drawings show a 30 x 8 lee board on both sides. The text in the book (and Ive also read elsewhere) suggests that when sailing with these two narrow boards, you can leave them down all the time, once you have found the balanced position. If this is right, how should they be shaped? If I have a foil shaped board down on both sides, they would be pulling against each other. Maybe Im worrying over nothing. I cant imagine that it will be an efficient sailing craft and perhaps I should just shape the boards to give a smooth water flow over them. Before I started reading about foil shapes, I imagined lee boards worked by just being a large surface area which resisted the sideways push (when looking at sailing barges etc, I had never noticed a foil shape to their boards.)
    I know some people want to sail efficiently and like to do things properly, and have the most efficient sail etc. but to be honest, that is not my priority. Im going to make my own sail and when Im using it, it will be the best sail in the world until I make a better one (because I made it). It will have two leeboards, whatever shape they end up, so I suppose Im not really asking for advice, but I would really like to understand this business about leeboard shape. Its the sort of thing that goes round and round in my head and Im sure there is some logic that Im just not seeing....... Help!


    Sam

  2. #2

    Default

    It does give lift but not ideally as the sailor would have to flatten the boat to counter act the lift.....

    It would be better described as directional stability in my opinion. Lift is an unwanted by-product that come from the board being shaped a bit like a wing to reduce drag.

    My leeboard is just a flat bit of wood. It isn't as streamline as a wing shaped board so creates more drag, but doesn't give lift.......

  3. #3

    Default

    If folk say it's a bit like a wing section, then it would be more like the wing of an aerobatic plane, with the curved profile on both sides, not flat underneath with the curve on top, like a 747 wing......


    Let's see what others think?

  4. #4
    Join Date
    Nov 2010
    Location
    grange over sands, cumbria
    Posts
    931

    Default

    A fixed leeboard is usually curved on both sides (ie is symmetrical) so that it can work the same on both tacks.
    The lift comes from the fact that when the canoe makes leeway, the water flowing over the board hits it at a slight angle (angle of attack). This angle deflects or bends the water flow by a few degrees. Because the water has been moved by the board, the water also pushes on the board (every action has an equal and opposite reaction) and this force on the board (lift) reduces the amount of leeway that the canoe makes. A hydrofoil (or aerofoil) section on the board allows it to bend the flow of water without stalling the flow (it can gently bend the water flowing over both sides of the board without slowing it down) whereas the flat board will only do this on one side. The flat board will not produce as much lift and will start to make more drag (slowing the canoe down).
    The board with a good hydrofoil section will allow the canoe to sail closer to the wind and also it will sail faster when close hauled.
    The flat board will still allow the canoe to sail into the wind though and unless you are racing against a similar canoe ( but one with a hydrofoil board) you may not notice the difference.

  5. #5
    Join Date
    Nov 2007
    Location
    cambs
    Posts
    1,549

    Default

    Excellent - thanks.
    It's beginning to be clearer now - Am I right that the ideal section would be similar to a long thin tear drop then, symetrical along the long axis? - Wheras I had been thinking of the shape as a wing section creating lift in the typical way shown on books about planes

    - but for what I want symetrically rounded on both sides will do - or easier still 12mm ply with rounded off front and back edges

    Sam

  6. #6
    Join Date
    Aug 2009
    Location
    Eastern England
    Posts
    1,167

    Default

    Quote Originally Posted by DaveS View Post
    The flat board will still allow the canoe to sail into the wind though and unless you are racing against a similar canoe ( but one with a hydrofoil board) you may not notice the difference.
    Dave explains things very well. Mine is a flat board (long rectangle, edges slightly tapered/rounded, in fact an ex-Optimist centre board IIRC) and is providing me with lots of fun sailing including upwind. But I'm not currently very interested in racing--just staying upright. As I see it, when/if I become interested in racing or come into a bit more money, I can upgrade. In the meantime I can admire others' beautiful hydrofoil boards.

    I like the sound of your PBK. Any pictures? How big a sail do you plan to put on it? (I've a similar open kayak I'd like to sail, but I've a feeling it needs a smaller sail plan than the 35ft expedition sail I'm using on the Apache.)

    All the best,
    Ian

  7. #7

    Default

    Quote Originally Posted by samB View Post
    Excellent - thanks.
    It's beginning to be clearer now - Am I right that the ideal section would be similar to a long thin tear drop then, symetrical along the long axis? - Wheras I had been thinking of the shape as a wing section creating lift in the typical way shown on books about planes

    - but for what I want symetrically rounded on both sides will do - or easier still 12mm ply with rounded off front and back edges

    Sam
    I wouldn't worry too much! Just get out there and have a bash!

  8. #8
    Join Date
    Nov 2010
    Location
    grange over sands, cumbria
    Posts
    931

    Default

    You may be ok with 1/2inch ply but i have seen boards break made from ply. The forces on a board can be quite high, and ply (especially cheap ply) can have a lot of the wood with the grain going across the board rather than along it. You might get away with it on a PBK though, especially if the rig isn't too large. Also there will be less strain on 2 shorter boards than one long one.
    If you dont want to bother with a full hydrofoil section, then i would round over the leading edge and taper the trailing edge down to about 1/8 inch.

  9. #9
    Join Date
    Dec 2006
    Location
    south Cumbria
    Posts
    1,205

    Default

    This classic film tells us how foils work - just look at the bit between 4 mins and 6.20 - includes the symmetrical foil/angle of attack stuff:

  10. #10
    Join Date
    Dec 2006
    Location
    south Cumbria
    Posts
    1,205

    Default

    I had a PBK with a sailing rig for a couple of years. I think it was about 14 ft with a modest sail plan, twin leeboards and a rudder. I only sailed it a couple of times, as a respectful nod to their past popularity and place in UK canoeing history - it was a bit tender and I always felt I wanted to move sideways more than the cockpit width allowed, to get it sailing better. Reaching and running were good, but beating was hardly worth it - might as well use a double paddle as it was easily driven.

  11. #11
    Join Date
    Aug 2009
    Location
    Ipswich, Sunny Suffolk
    Posts
    1,354

    Default

    Cheers for the link Keith, excellent. One or two things still confuse me though. In the video it states that a symmetrical aerofoil creates zero lift lift until the angle of attack is increased. But doesn't a boat's lee board effectively have zero angle of attack? That is to say the board is aligned with centre of boat and thus perpendicular to the oncoming mass of water. As an example, if the wind is coming from the right of boat, the force of the wind pushes the mast and front of boat round to the left so isn't the lee board angle of attack increased to the left as well, creating lift on the left (lee) side of board so pulling the boat towards the lee side?

    Obviously I'm not disputing that aerofoil section lee boards work, just a bit confused still about how they work.

    Edit: Just googled it and first site I got was this one: http://www.boat-links.com/foilfaq.html containing the following passage:

    "The main difference between a "thin flat plate" and a NACA foil is that the foil will generate lift, i.e. power, at a higher angle versus the boat's direction. Where a plain flat rudder will stall and simply slow you down somewhere around +/- 5 to 10 degrees from center, a NACA foil will be effective over maybe twice that range. Your boat's rudder will work better. Tacking will be easier. A little bit of weather helm translates into more sideways 'push' upwind. As a leeboard, centerboard or daggerboard the difference between the plate and foil would be much less pronounced because the boat is usually moving "crabwise" through the water at a much smaller angle than you'd use at the helm when tacking. As long as it doesn't vibrate, a flat plate is probably as effective and a lot less hassle than a shaped foil section."

    hmm, I'm definitely confused now.
    Last edited by fredster; 27th-September-2011 at 07:16 AM.

  12. #12
    Join Date
    Nov 2007
    Location
    cambs
    Posts
    1,549

    Default

    Thanks to you all
    Ian I hope to see you on the water sometime Im local to you and usually recognise the places you refer to in your write ups Ill be looking for advice support etc when Im on the water. The PBK will be reported in self builds when I finish. Im terrible at taking pictures of my projects but have been trying harder this time! It will have somewhere in the region of 20 25 square foot sail.

    Wavecloud Yes I will just have a go. I know I might find sailing a right faff or it might be brilliant but Ill never know unless I try.

    DaveS- Ill try plywood first as I can obtain it without trouble. Thanks for the thoughts about grain direction.

    Windorpaddle the video bit you highlighted made perfect sense with the pictures (but see below) Ill now sleep easier at night. I think I might appreciate my PBK more than you did as sailing will be a completely new experience: - I wont be aware of what my boat cant do while Im sure you could see all its faults.

    Fredster (and this is where I might be making myself look stupid) I think that as the boat moves forward , the sideways push of the wind changes the angle of attack from in line, to a slight angle and produces the lift shown at 6.03 6.24. (Someone tell me Im right!!) but Im glad its not only me who has to understand these things!
    Sam

  13. #13
    Join Date
    Aug 2009
    Location
    Ipswich, Sunny Suffolk
    Posts
    1,354

    Default

    Quote Originally Posted by samB View Post
    ...I think that as the boat moves forward , the sideways push of the wind changes the angle of attack from in line, to a slight angle and produces the lift shown at 6.03 6.24.
    Agreed, but isn't the angle of attack increased (and creates lift) in the wrong direction (ie towards lee) ? The way I understand it what you want is the lift to be towards windward, to counteract the leeward travel. Oh well, more googling called for I think.

  14. #14
    Join Date
    Aug 2009
    Location
    Eastern England
    Posts
    1,167

    Default

    Quote Originally Posted by samB View Post
    Thanks to you all
    Ian I hope to see you on the water sometime Im local to you and usually recognise the places you refer to in your write ups Ill be looking for advice support etc when Im on the water. The PBK will be reported in self builds when I finish. Im terrible at taking pictures of my projects but have been trying harder this time! It will have somewhere in the region of 20 25 square foot sail.
    It would be a pleasure to meet you. You don't live in Hemingford Abbots, do you? A long shot, I know, but I remember paddling my Klepper past a gentleman there a year or two ago who inquired whether it was a PBK and said he had one he was intending to repair/refit at some point.

    I tend to try and get out paddling on weekdays rather than weekends as I work odd shift patterns and my family tends to want me when I'm not working weekends. The rivers tend to be uncrowded then as well.

    In any case, all the best with it. I'll be looking out for a PBK with or without sails.
    Ian

  15. #15
    Join Date
    Nov 2007
    Location
    cambs
    Posts
    1,549

    Default

    Quote Originally Posted by idc View Post
    It would be a pleasure to meet you. You don't live in Hemingford Abbots, do you? A long shot, I know, but I remember paddling my Klepper past a gentleman there a year or two ago who inquired whether it was a PBK and said he had one he was intending to repair/refit at some point.

    Ian
    Right river but too far west - I'm at Ely ....... and please don't call me gentleman - i'll be getting ideas above my station!!

  16. #16
    Join Date
    Nov 2007
    Location
    cambs
    Posts
    1,549

    Default

    Quote Originally Posted by fredster View Post
    Agreed, but isn't the angle of attack increased (and creates lift) in the wrong direction (ie towards lee) ? The way I understand it what you want is the lift to be towards windward, to counteract the leeward travel. Oh well, more googling called for I think.
    ...... and I was looking forward to a good nights sleep: Never mind - bring out the experts again!
    Sam

  17. #17
    Join Date
    Dec 2006
    Location
    south Cumbria
    Posts
    1,205

    Default

    Sorry guys only just finished work and was hoping that Dave might have taken this on - he's a better physicist than I'll ever be..

    I found a bit that might help:

    The foil does not simply resist leeway. The boat's forward motion, produces a water flow that strikes the lee side of the centreboard, and that underwater “foil” with its angle of attack thus produces a “lift” force on the upwind side.

    This a heavily edited extract from this document - just look at diagram 2 and it should be clearer.

    http://www.arrowtech.com.au/jc.pdf

    If that's not enough then get into this:
    http://www.paulzander.biz/centerboards.html


    Last edited by windorpaddle; 27th-September-2011 at 10:10 PM.

  18. #18
    Join Date
    Aug 2009
    Location
    Ipswich, Sunny Suffolk
    Posts
    1,354

    Default

    Right, think I understand it now. In addition to the article Keith linked to I found this site was very useful: http://blog.everydayscientist.com/wp...cs-sailing.pdf

    Figure 1 is basically a simplified version of the one in Keith's linked-to article, and explains it well. Got there in the end.

  19. #19
    Join Date
    Aug 2009
    Location
    Eastern England
    Posts
    1,167

    Default

    Quote Originally Posted by samB View Post
    Right river but too far west - I'm at Ely ....... and please don't call me gentleman - i'll be getting ideas above my station!!
    Would it help if I emphasised I was calling the gentleman I met a gentleman, not your good self!
    I'm looking forward to spotting your pbk out on the water.
    All the best,
    Ian

  20. #20
    Join Date
    Nov 2007
    Location
    cambs
    Posts
    1,549

    Default

    My goodness - 5.54 am - I never knew that time existed!!! - you do work strange hours if you're up and about then!
    Sam

  21. #21
    Join Date
    Nov 2007
    Location
    cambs
    Posts
    1,549

    Default

    Quote Originally Posted by windorpaddle View Post
    If that's not enough then get into this:
    http://www.paulzander.biz/centerboards.html

    I take my Hat off (if I had one on) to anyone who can read and understand this. To me it looks like gobbledygook. I think I have more chance of understanding - well - I can't think of anything complicated enough! - but luckily the first link had pictures (graphs don't count), and as we know they are worth a thousand words, so although I wouldn't be able to explain it to anyone else, I think I might have my head round it, at least for today and until I forget. I think it was Einstein who said along the lines of "there's no point in remembering something that you can easily look up" and was it Homer Simpson who insisted that for every new thing you put into your brain, you had to forget something previously learnt?
    Sam

  22. #22
    Join Date
    Aug 2010
    Posts
    1,794

    Default

    I have read all the above post.
    I think that everything points the a shaped foil like a tear-drop shape correct ?
    or is it the same as an plane wing.?
    The other thing i never noticed is what is the length of the board ?
    I expect to be shot down with the answer there all different sizes but what would the average size be.

    Or is there somewhere on the internet i will be able to find more details.?

  23. #23
    Join Date
    Nov 2010
    Location
    grange over sands, cumbria
    Posts
    931

    Default

    My leeboards are 4ft to 4ft 6inch long, including the handle. The handle is 10inches long.

  24. #24
    Join Date
    Aug 2010
    Posts
    1,794

    Post

    Quote Originally Posted by DaveS View Post
    My leeboards are 4ft to 4ft 6inch long, including the handle. The handle is 10inches long.
    Many thanks for the reply.
    I am trying to get together all the bits required to make a sailing Canoe.
    I am at present working on the stabilizers .

    I managed to find again average sizes off the forum and started.

    Then I would like to make a rudder and a Leeboard But cant find many details on like sizes.
    I am thinking a canoe approx 15 foot..
    So I guess everything is about average ..

    Any chance of a picture of your Leeboard so I can see what it is i hope to make.
    Many thanks
    Again.

  25. #25
    Join Date
    Dec 2006
    Location
    south Cumbria
    Posts
    1,205

    Default

    Some pics of one of my leeboards on this page:
    http://homepages.rya-online.net/ocsg...ing_canoes.htm

    Or one of Dave S's commercially available ones on:
    http://www.solwaydory.co.uk/products/accessories/

  26. #26
    Join Date
    Aug 2010
    Posts
    1,794

    Default

    Quote Originally Posted by windorpaddle View Post
    Some pics of one of my leeboards on this page:
    http://homepages.rya-online.net/ocsg...ing_canoes.htm

    Or one of Dave S's commercially available ones on:
    http://www.solwaydory.co.uk/products/accessories/

    Many thanks for the links.
    And the funny thing is I have just this second looked at the solway dory page.

  27. #27
    Join Date
    Dec 2008
    Location
    Nr Hampton Court, West London
    Posts
    3,084

    Default

    With my yachty hat on, the purpose of a keel, dagger board, centre board, lee board, is to prevent the boat slding sideways when you try to sail accross or towards the wind. In the case of a keel, it doubles up as a depositaory of ballast to stop the thing turning over. Without ballast you have to rely on hull shape, and canoes have little on no sideways resitance. The shape of the thing matters not a lot. It is largely a question of area, but different shapes will be more or less good at allowing steering. A long shallow board will stop sideways motion, but resist truning. A deep short board of the same area will resist sideways motion as well, but will not inhibit steering..The only other basic thing is that reduction in drag is good, so streamilining (which would produce an aerofoil type shape) would be good.

    If we consider a leeboard, positioned on one side of the boat only, in order to maintain the freedom of movement in the boat (no dagger board or centreboard case) then if it were to produce lift to windward, (which is what people mean I think, not hydrodynamic lift as seen is foiling moths, for, example.which is upwards)then on the other tack it would produce "lift" away from the wind, which is to no ones advantage. If it were to be very deep, then the load from the resistance to leeway would be greater than that from a shallower board. Big, commercial size leeboards are LEE boards, lowered on the appropriate lee side, to that the action between hull and board is in compression, and that of the pivot is in tension. Both are easy to resist. In canoe, with "tiny" forces, a windward board attachment merely needs adequate design, (something not always acheived initially if posts on the site are to be believed). A different solution could be that polyinesian solution of a proa. wich in order to have stability without excess drag, maintains the outrigger to leeward, and instead of tacking, reverses, using a steering oar at either end., to that you reverse the canoe and steer from the other end.

    Now to the interesting consideration of angle of attack. It would seem pretty obvious that a slight front to windward alignment would help to lift the boat to windward. In the racing dinghy world, huge amounts of time, and quite a bit of money has been spent on trying to acheive this with centre or dagger boards, and it has been found that if, withing the fixed width of the box, the part of the board within the box is narrow at the front and thick at the back, the water pressure on the rest of the board in the water, will push the front to windward, thus acheiving the required result. Simple. However it increases drag, and of the several classes whose rules would permit it, few have adopted what are know (for no good reason) as gybing boards.

    However, in the yacht world, where the extreme designs of the moment feature "canting keels" which have little resistance to leeway, extra dagger board or boards are used to provide this resistance, and they are usually in pairs, the leeward one being employed when going to windward. I suggest that anyone interested in the curved "foils" which provide vertical lift, used in some lightweight racing small catamarans, and in some very big ones, and some Open 60s (open as in rules, not as undecked) might care to PM me before the sheer lenght of this post puts readers to sleep.

    Impcanoe

  28. #28
    Join Date
    May 2007
    Location
    Deepest darkest Wales
    Posts
    3,921

    Default

    If your interested in the topic then these two books are worth reading.
    1 - High Speed Sailing - Norwood
    2 - Icarus - the boat that flies - Grogono

    The maths gets steep - fast.

  29. #29
    Join Date
    Dec 2011
    Location
    South Coast
    Posts
    328

    Default

    Quote Originally Posted by Impcanoe View Post
    With my yachty hat on, the purpose of a keel, dagger board, centre board, lee board, is to prevent the boat slding sideways when you try to sail accross or towards the wind. In the case of a keel, it doubles up as a depositaory of ballast to stop the thing turning over. Without ballast you have to rely on hull shape, and canoes have little on no sideways resitance. The shape of the thing matters not a lot. It is largely a question of area, but different shapes will be more or less good at allowing steering. A long shallow board will stop sideways motion, but resist truning. A deep short board of the same area will resist sideways motion as well, but will not inhibit steering..The only other basic thing is that reduction in drag is good, so streamilining (which would produce an aerofoil type shape) would be good.

    If we consider a leeboard, positioned on one side of the boat only, in order to maintain the freedom of movement in the boat (no dagger board or centreboard case) then if it were to produce lift to windward, (which is what people mean I think, not hydrodynamic lift as seen is foiling moths, for, example.which is upwards)then on the other tack it would produce "lift" away from the wind, which is to no ones advantage. If it were to be very deep, then the load from the resistance to leeway would be greater than that from a shallower board. Big, commercial size leeboards are LEE boards, lowered on the appropriate lee side, to that the action between hull and board is in compression, and that of the pivot is in tension. Both are easy to resist. In canoe, with "tiny" forces, a windward board attachment merely needs adequate design, (something not always acheived initially if posts on the site are to be believed). A different solution could be that polyinesian solution of a proa. wich in order to have stability without excess drag, maintains the outrigger to leeward, and instead of tacking, reverses, using a steering oar at either end., to that you reverse the canoe and steer from the other end.

    Now to the interesting consideration of angle of attack. It would seem pretty obvious that a slight front to windward alignment would help to lift the boat to windward. In the racing dinghy world, huge amounts of time, and quite a bit of money has been spent on trying to acheive this with centre or dagger boards, and it has been found that if, withing the fixed width of the box, the part of the board within the box is narrow at the front and thick at the back, the water pressure on the rest of the board in the water, will push the front to windward, thus acheiving the required result. Simple. However it increases drag, and of the several classes whose rules would permit it, few have adopted what are know (for no good reason) as gybing boards.

    However, in the yacht world, where the extreme designs of the moment feature "canting keels" which have little resistance to leeway, extra dagger board or boards are used to provide this resistance, and they are usually in pairs, the leeward one being employed when going to windward. I suggest that anyone interested in the curved "foils" which provide vertical lift, used in some lightweight racing small catamarans, and in some very big ones, and some Open 60s (open as in rules, not as undecked) might care to PM me before the sheer lenght of this post puts readers to sleep.
    An eloquent appraisal of some of the more exotic possibilities for sailing canoe leeboards. However, unlike IC10s, sailors of cruising sailing canoes are usually little interested in very marginal increases in performance at the expense of simplicity, portability, ease of use, etc. Cruising sailing canes with 5M sails (or thereabouts) are primarily cruising or expedition boats. A very wide variety of leeboard, centreboard, and offset board arrangements have been tried on sailing canoes over the last 20 years and the exponents of each have almost always reverted back to a single longish leeeboard. Solway Dory make very good leeboards and fixings of this type and they have proven reliable and robust. Many in the OCSG have made their own to a similar sort of design.

    My general advice would be to stick with a very well proven design for cruising sailing canoe leeboards unless some combination of experimentation, tinkering and racing is the aim.

    However, I'm also sure inventive minds in the OCSG will continue to come up with new ideas for boards and sailing canoes in general - continuing the advance of these great lightweight expedition boats.
    Last edited by GavinM; 22nd-May-2012 at 07:32 AM.

  30. #30
    Join Date
    May 2007
    Location
    Deepest darkest Wales
    Posts
    3,921

    Default

    Quote Originally Posted by Impcanoe View Post
    ....A different solution could be that polyinesian solution of a proa. wich in order to have stability without excess drag, maintains the outrigger to leeward, and instead of tacking, reverses, using a steering oar at either end., to that you reverse the canoe and steer from the other end.........
    Impcanoe
    Putting my official pedant hat on - Polynesian proas keep the outrigger (ama) to windward.

    And their approach to leeway reduction is truly fascinating.
    http://harmenhielkema.blogspot.co.uk...sertation.html << Good acccount

  31. #31
    Join Date
    Dec 2006
    Location
    south Cumbria
    Posts
    1,205

    Default

    Great link, Doug! I'll have to have a proper read when I'm not at work!

    One or two of our OCSG people have tried the "shunting" double-ended proa approach and while they work the usability factor, which Gavin mentions above, is not so good. Especially when tacking in a relatively limited width channel or even narrow lake - coming to a dead stop and then getting going again in the other direction means you lose both way and position up to windward - and if sailing with other "western" style canoes that tack thro the wind without losing much way the difference is very marked.

  32. #32
    Join Date
    Apr 2009
    Location
    West Yorkshire
    Posts
    3,652

    Default

    What a great photo...



    ...and I love the dress code

  33. #33
    Join Date
    Dec 2008
    Location
    Nr Hampton Court, West London
    Posts
    3,084

    Default

    DougR You're right, of course, but wasn't there a transatlantic race boat, many years ago, which had the outrigger to leeward, so that no one had to go "wingwalkin" in the dark, or storms. It still "tacked" by changing ends. I might have to go into research mode, for sailing canoe?????

    Peter
    Impcanoe

  34. #34
    Join Date
    May 2007
    Location
    Deepest darkest Wales
    Posts
    3,921

    Default

    Type sometimes known as an "Atlantic" proa - "Cheers" Dick Newick 1968?

  35. #35
    Join Date
    Dec 2011
    Location
    South Coast
    Posts
    328

    Default

    Some parts of this thread remind me of; "Well, it may be all right in practice, but it will never work in theory." - Warren Buffet.
    Last edited by GavinM; 22nd-May-2012 at 05:15 PM.

  36. #36
    Join Date
    May 2007
    Location
    Deepest darkest Wales
    Posts
    3,921

  37. #37
    Join Date
    Dec 2011
    Location
    South Coast
    Posts
    328

    Default

    Apologies if I've offended. I'm not much of a theoretician when it comes to sailing boats. I prefer sailing and get excited about incremental practical improvements which improve the experience of sailing and the capabilities of my boat. Yet, I also realise design evolution depends on theory, as well as practice.

  38. #38
    Join Date
    Dec 2008
    Location
    Nr Hampton Court, West London
    Posts
    3,084

    Default

    You see, without this thread I'd never have dredged "Cheers" and Dick Newark from my dodgy memory. One man's meat is another man's poison. Thanks DougR

    Impcanoe

  39. #39
    Join Date
    May 2012
    Location
    Surrey UK
    Posts
    4

    Default

    Hello. I'm thinking I'll get a windsurf sail etc. Make an outrigger and hope to steer with a paddle. My 4m Sea Eagle is inflatable and quite strong. If I make a wooden cage to go midships I could step the mast in it and use it as an attachment point for leeboards and outrigger.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •