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PostPosted: Sun Feb 09, 2014 1:35 pm 
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Location: Auckland NZ
I thought I would ask what tips and techniques all you avid kayak sailors have for squeezing the last drop of sailing speed out of your boat?

I am not talking about pedalling or paddling while sailing; just pure sailing.

I am also not that interested in using amas and akas to provide more lateral stability: I am only really interested in sailing the kayak as a kayak.

I am interested in things like tweaking the rig, increasing sail area, techniques for hiking out, improving sail shape, improving the hydrodynamics of the hull etc etc. ...anything along those lines which is designed to improve sailing performance...


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PostPosted: Sun Feb 09, 2014 3:04 pm 
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I would start with a sliding seat


Need inspiration ?


http://www.intcanoe.org.uk/index.php?op ... &Itemid=79




Sent from my PG86100 using Tapatalk


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PostPosted: Sun Feb 09, 2014 4:27 pm 
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  • - Add telltales towards the trailing edge, and put a few more on the sail towards the leading edge at various heights. Learn what they mean and how to use them. As a start - if the inner one is limp, pull the sheet in; if the outer is limp, let the sheet out; if both are flying, you're doing well; if both are limp, see a doctor :lol:
  • - Pull the board up unless you're going upwind, or worried about a lee shore.
  • - Look at moving your weight around - out on tramps/hakas to keep the mast/boat as upright as possible and therefore catching the wind more (but putting more strain on the mast and fitting). Also work out where weight fwd/aft is best placed - maybe move the beer esky or even leave it behind :o
  • - In predominantly light air, look at the threads about adding a jib or spinnaker. Also look at the thread about using both peddle and sail working together to bring the apparent wind forward


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PostPosted: Mon Feb 10, 2014 7:38 am 
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Macarthur, above is on track with his response. Especially in the area of adding weight (ballast) in appropriate places to increase the length of the boat at waterline thus increasing its potential hull speed. I had someone take pictures of my boat from the side while I was sailing it. That provided me with a lot of information on where the weight needed to go.

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2010 Oasis
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PostPosted: Mon Feb 10, 2014 3:34 pm 
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Joined: Sun Aug 12, 2007 5:17 pm
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Location: Auckland NZ
Thanks for the responses guys.

I think I was really after more in-depth insights into exactly what people do to get more speed i.e. not ideas/concepts/basics but practical suggestions.

I know well enough how to sail, the meaning of telltales on sails, the importance of ballast, weight distribution, hiking out etc and I have a system for staying the mast so that I can set a jib etc etc.

What I was really after was any suggestions as to exactly what practical steps have proven to improve speed whilst sailing and I precluded the use of pedals/paddle/akas/amas in my question because I am really only interested in what works on the hull on its own under sail only - i.e. trying to isolate the sailing performance. I am not particularly interested in making wholesale modifications to the boat either, so while a sliding seat may work wonders, it would really be a step too far for me!

I was hoping that this might surface suggestions about battens, reefing, stays, sheet angles, barberhaulers, drivewell fairings/fin position, daggerboards, spinnakers/genoas/kites or WHY... dunno what I was expecting really but I was hoping that there may be a bunch of closet rig tweakers lurking out there incognito who would be willing to share their secrets :wink:

And in case you are wondering, my hidden reason for asking is to prepare New Zealand's entry for the next Americas Cup... :lol:


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PostPosted: Tue Feb 11, 2014 3:16 pm 
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stobbo :
Very interesting question, there are upsides to everything and also downsides. For example on a kayak when you add more sail area you run into the problem of the boat wanting to tip over, since there is no weighted keel like in a monohull, or AMA's, or any ability to hike out like you would on a laser or class A, your going to go over unless you are really fast to depower the sail (I'm usually not fast enough and get wet a lot).
Adding a jib does increase your sail area and speed but unfortunately it also increase the lateral force (heeling moment). With just about any standard sail about half the power generated produces lateral force (heeling moment), this is physics and is pretty difficult to work around, especially if you don't want to add any AMA's.
I have messed around quite a bit with kayak sailing and have figured out quite a few things that you might want to think about.

First off if you don't want AMA's there is a way to add a weighted keel to the boat which makes it almost impossible to tip over. I had a 25 lb weight suspended about 1 foot under my Oasis, and that made the boat nearly impossible to tip over, something like this is actually pretty easy to make and doesn't create a lot of drag. I used a PVC tube filled with 25 lbs of lead shot (scuba weight belts), I just put a cap on each end and suspended the weight on spectra string, from the back of the front mirage drive hole and the front of the rear mirage drive hole, the spectra string (rudder line) is very strong, and if you beach the boat the keel weight just pushes out of the way, since the weight is shaped like a torpedo, there is very little drag. The string doesn't interfere with the mirage drives at all.
Another thing that you should look into is possible adding a wing sail vs a conventional sail. One of the benefits of wing sails is there is almost no lateral force from wind with a wing sail, so it is much less likely to tip over, plus wing sails are much more efficient than standard sails.
By using a combination of a keel weight and a 30 sq ft wing sail (equal to a 50-60 sq ft conventional sail) you could really have a nice sailing rig.
Here is a pic of my Tandem Island kayak with a 33sq ft furling wing sail and a 50 lb swinging keel weight (the weight is adjustable side to side to control trim). It actually works pretty well except next time I won't make the sail 19 ft tall (a shorter square top sail ( like the Hobie Kayak sail) would be a little less top heavy and tipsy).
Image

Just to show how much more stability the weighted keel gives you, here is a pic of me sitting on the edge of my kayak, the 50 lb keel weight prevents the boat from tipping over. The deeper the weight is, the more stability you get, I think mine is about 18" deep in this pic. Of course the TI is a huge boat (with huge sails) so it needs much more weight, I had 25 lbs on my Oasis and it would do the same as shown here with the TI ( I sold the Oasis) otherwise I'd jump in the pool and take a pic of me on the rail of the Oasis.
Image

Hope this helps you, your options are otherwise fairly limited beyond slipping a fiberglass rod into the lower hem of your Hobie kayak sail ( Like a mini-boom --- several have done that and it works pretty well), of course you would need to remove it in order to furl the sail. I had a 40 sq ft spinnaker on my Oasis for a while, but I went swimming a lot with it (even with the weighted keel), since you can't hike on a kayak it makes sailing a bit more challenging.

Bob


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PostPosted: Tue Feb 11, 2014 3:26 pm 
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Location: Winston-Salem NC
More speed has a lot to do with better sail trim and helm control. We all know how to do it but one will outsail another for no apparent reason. Why? Tom Kirkman posts here frequently on the fishing and Island forums. I sailed with him once last winter in his Tandem Island on a fishing trip. I know how to sail. But whenever I would turn the controls back over to him, the boat would speed up noticeably. Why? I couldn't see what he was doing that I wasn't but the boat always went noticeably faster under his control.


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PostPosted: Tue Feb 11, 2014 4:37 pm 
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Location: High Point, NC
You didn't turn your hat around backwards. The boat will go faster if you turn your hat around.


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PostPosted: Thu Feb 13, 2014 3:13 pm 
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Location: Auckland NZ
Dammit, why didn't I think of that?! :roll:


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PostPosted: Thu Feb 13, 2014 3:19 pm 
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Seriously, sail trim. Assuming the boat itself is well trimmed/balanced, focus on sail trim. A couple inches is all it takes to make a huge difference in speed. And remember that sail trim is an ongoing thing. You can't just set it and forget it, if you want to go as fast as possible.


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PostPosted: Fri Feb 14, 2014 8:13 am 
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I once sailed a 8' El Toro dingy many years ago and learned that the "good sailors = fast sailors = seat of the pants feel of the boat and conditions"......the moral is "a Slow boat will go fast with a good sailor".... :wink:

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PostPosted: Thu Feb 20, 2014 11:06 am 
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This is a really fascinating read, and I am absorbing all I can from the discussion.

I want to especially thank fusioneng for the detailed and insightful post.


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PostPosted: Tue Apr 22, 2014 11:30 pm 
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I'm guessing your fit, and love racing the sail kayak. I like to as well and try any simple solutions to get the max out of sailing with minimal mods.

Here is what I did on my first Revo 13 setup:

Changes that have improved sailing speed and more importantly efficiency:

- Replacing padeye directly behind aft hatch with a pulley.

- This pulley feeds the mainsheet through a series of fixed pulleys down the right side of my kayak to approximately just forward (and in line) of the mirage drive well. This allows me to control the lines from a forward feeding mainsheet system as opposed to down my side or to the rare. Much easier to work the loads.

- No option to tie off mainsheet, this dangerous and likely see me being unprepared for drastic heeling. I am always on edge (similar to high wind laser sailing) when sailing my kayak.

- Reversed the steering to match normal sailing dinghy tiller setups. Attached a 60cm long tiller attachment to steering joystick to allow me to hike out better on starboard side. Great setup.

- Add rubber support mat between bottom of mast receiver and bottom of hull. This protects the hull ‘nub’ from shearing off. I also shaved the bottom of the mast receiver to be round without sharp edges to minimise the chance of it cutting into the rubber (or hull if its exposed). This has worked great.

- Attach the downhaul line that connects the sail to the hull. This improves sailing capability due to the lesser chance of mast up/down movement.

Future changes:

- Add Jib. Could help turning without drive, cant see it doing much else except at low wind levels.
- Add boom to support sail. This will help downwind for sure.
- Add cross bar across front sail mount hole that will strengthen the masts ability to take stronger winds as well as spread load from kayak mast receiver area. If people haven't noticed, the bottom hull, mast receiver and kayak plastic around the mast area takes a battering in higher than recommended winds. In fact I nearly sheared off the knob of plastic within the hull that connects the mast receiver to the bottom of the hull.

My new project is to setup a trimaran for long distance trips. But I like to take off the AMA's and race around the bay with nothing bu t the sail.


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PostPosted: Thu May 08, 2014 9:05 pm 
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I'm guessing you're familiar with some of the old sailing posts re: boom-bats, changing the sheeting angle (on the Adventure) for a better luff, use of the scallops in the footwell for max hiking out, re-cutting the sailing rudder to improve the aspect ratio, reduce drag. There is even a post about making a traveler for the mainsheet block. I always weight the bow (inside) -- about 3 kg. and tape the leading 2/3 of the seat scuppers to clean up the hull bottom. If you're using the daggerboard and no fins, you can also tape over the drivewell opening with clear packing tape. If that doesn't bring the America's Cup home, I don't know what will! :D


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