Centreboard Removal

[Ozzie]

Ozzie.
The reason for the WA boats having a smaller has more to do with helm. And not just the centre of effort. By having the centre board with the standard rig, makes for a lighter helm"....................... The pressure on trying to helm the boats with the full size rig without the board is huge..........

So, the answer is, if you are going to sail the boat without a board lowered, I would be reducing sail area immensely, or better still go and buy a power boat.

I have sailed with the board stuck at the end of the season quite a few times [Name deleted as user no longer registered] and have not noted excessive weather helm, certainly not enough to go back to power boats. Emrys cb has been stuck for some time and he’s not mentioned it either, but he may come in here with his own observations.

You should try it yourself Kieron and see what you think. If you have a wooden plug I wasn’t suggesting it be water tight but have a forward and aft drain hole. The main function of the plug would be smooth water flow around the cb slot. Like most things experimenting is the key. It’s part of the fun of owning a boat, you can play all you like with modifications without the bureaucratic meddling that car modifications must deal with.

In regards to boat setup and rigging, I have always suggested to those with new boats to try the setup on the boat for a while and see how it suits you. You may like it you may want to change it to suit yourself. No two boats on this forum are probably set up exactly the same.

[Ozzie]

I stand corrected [Name deleted as user no longer registered] Apologies. Up to that post, posts had been referring to an “unbalanced “ helm which I generally consider to be weather helm . However I have not significantly found the helm unbalanced or heavy sailing board up . As you are saying you don’t ever sail this way or I’m assuming not sailed the Investigator 563 that way I was curious as to what are you basing this statement on ? I am basing my statement of my own personal experiences with my particular boat which is all I can report on in confidence. Which is why I suggested nothing lost if Kieran tried this out himself. The unguarded part of rudder only comes below the long keel by a small percentage I’m surprised it was making such significant difference.

By the way, no question that I do experience the additional leeway but I expect that.

We have not had significant reports of the WA boats sailing badly as far as I can find . Ray do you know the difference in sail area for the WA boats?

[Peter T]

I wonder how many people actually know the working of a yacht. I thought I might explain a few things in as
simple terms as possible about the balance of a yacht to help those who may not know to understand.
First there is Centre of Lateral Resistance (CLR) and Centre of Effort from the sails (CE). CLR is the point on a yacht's profile where you can theoretically push the boat sideways through the water if you could push it with your finger on the spot marked CLR, where the boat would go sideways without the bow or stern effecting the sideways movement.
The CE is a point worked out by triangulation and the area of the sails which is the combined effect of the centre of effort of both headsail and main. Also a theoretical point where you could push the sails sideways ( which of course you cant)
The yacht must be designed so that it is balanced as best as possible for most conditions. The more wind you get, the heavier the helm should be.
The rule of thumb for designers is that the combined CE is between 5% - 15 % of the water line length forward of the CLR
If the CE is too far forward of the CLR, the boat will want to turn and head down wind. This is called Lee helm and in reality it is terrible as you are continually turning the rudder away from you trying to bring the yacht back onto the wind. Conversely, if the CE is too far aft of the CLR, then the opposite happens and the boat keeps wanting to turn into the wind which loads up the weight on the tiller and you have to fight to stop the boat from going about, because you are constantly trying to fight the boats tendency. This is weather helm and makes the helm really heavy. Both these conditions causes drag, especially on the rudder and slows the boat down as well as making it uncomfortable to operate.
Now, it gets a lot more complicated that this. The shape of the hull is not uniform over its length. Also the yacht has a keel, centreboard and rudder.
Most yachts have foil shaped rudder and keel etc which, when the boat moves through the water causes lift, as the sailes do so. All of this effects balance.
When the yacht heels over, the under water profile shape of the hull changes.
All this causes the CE of the sailes ( because their profile shape to the wind has reduced) and the CLR of the hull to move from what it is when stationary and vertical.
This is why normally you will find that a good average is to have the CE around 10% of the waterline length forward of the CLR.
As the heeling motion increases, the wind increases and the angle to the wind changes. This balance changes and causes more heavy helm.
I have not spoken of the wind that the yacht creates by moving forward, true wind or apparent wind as I don't want to get too complicated, but as you can see, there is great importance on all aspects of the yacht that can effect the helm weight. The depth of the centreboard, the hull shape, the size and shape of the rudder all have a big effect.
The position of the mast, the size of the main and size of the jib all effect the yacht's balance.
I can tell you about my last yacht. Every example of this design I have come across had so much weather helm that they were virtually impossible to sail comfortably. I won't mention its design, but it is a common Australian design but when they designed this particular model, what they did was to add the area of the No1, No2 and No3 headsails together to work out the CE. As you will now understand, what that did was to falsely move the overall CE backwards far further than it should have been causing the very heavy weather helm.
I proved this by working it out off the plans for myself and the only way I could get the CE to be where the plans showed it was to add the area of the 3 headsails together which gave me their exact CE shown on the plan.
Some owners of these yacht tried things like raking the mast forward making the boat look ridiculous, adding a 4ft bow spit but they all had horrible weather helm. When I purchased my boat, it was a bare fibreglass hull sitting in a cradle with no bulkheads, deck or anything.
The keel of my boat had been modified to make it shorter and gave the 24 ft boat a draft of 6 ft. I added about 8 inches to the back edge of the keel by glassing a piece of foam to it, used a larger rudder and fitted the main bulkhead which supports the mast about 10 inches further forward than the plan showed. When I rigged the boat, I made the mast step adjustable, I used old galvanised rigging of another old boat I bought for parts with short length of chain at the deck so that ever everything could be adjusted.
When I sailed this yacht exactly as I had redesigned it in 10 to 15 knots of breeze, I could let the tiller go and it would sail a straight course on its own. Perfect balance, so I then went and had new stainless rigging fitted.
I hope all this has helped those who didn't know such things understand that a lot of changes you make to any boat will probably have a marked effect on its performance.
The beauty of our Investigators is that we have the ability to alter the weight of helm we get in differing conditions and sailing angle to the wind by adjusting the amount of centreboard we lower. Play with it and see the result you get.Certainly, the lower it is the quicker the boat will turn.
Cheers

[Ozzie]

Thanks gents for that additional input. Different opinions are always welcomed here but reports of persons own personal experience are valid as well. The post is not locked in any way and any further input is welcome, within our guidelines.

Kieran seems to have made a decision based on his reading of the information here, which is great. The last thing we want to do is have people avoid asking or stating opinions.

The great amenity of these boats is that they can be enjoyed at all levels of competence.

[Ozzie]

David, you are so correct. Reading the past few posts here makes me wonder how many people actually know the working of a yacht.

Peter, I think in the spirit of my previous post, I.e. that we do not wish to discourage people from asking questions, it is really unnecessary to preface your post with personal attacks on what has been previously said and simply provide the information you wish to give.

[Geoff]

It is interesting reading the different opinions. I bought my Investigator a bit over a year ago and had never sailed before. That's why my research led to my purchasing an I563. Like almost everything else I have ever done, I have learned by researching and doing. I am sure purists would object to the way I sail my boat, and to some of the little mods I have already made.

I don't care. I bought it to have fun with and it's a buzz. Half the time I am out I realize after sailing for hours I haven't dropped the cb, and have made many dozens of tacks and gybes in that time. I am not experienced enough to appreciate nuances, obviously. But no puppies died.

Like Ozzie said, it is such a pleasure to be able to experiment with what makes it good for you. Like doing up a car when we were young fellas. I have no interest in having the best or fastest yacht, but others no doubt will. I want a pocket cruiser to poke around islands like other Investigator owners have done and still do.

This forum has given me the confidence to do things to my boat based on the practical experiences of others, those who have openly relayed their experiments and experiences, successful and otherwise. So all good to express your opinions, even if you are personally convinced they are facts. But I really enjoy alternative viewpoints, especially based on real experiences.

I do hope everyone contributes their opinions and experiences, instead of holding back for fear of being called 'wrong'.

[Peter T]

I am totally amazed. Under no circumstances am I having a go at anyone here. All I was trying to say is that it became apparent to me that there are probably some people who might not understand the ramifications of making severe changes to a yacht's design that will effect the performance, handling and pleasure of sailing the thing. I was and still am, of the opinion that before anyone was to make such a change, that it would be in their best interests for them to be able to understand how a yacht's characteristics could be altered by such changes. My post was meant to be helpful and informative. It was never meant to upset anyone. I fail to see how knowledge of how something works can be harmful or upsetting to anyone.
If I have upset anyone or hurt anyone's feelings in any way, then I apologise, but the information I have given is based on facts. Anyone can google the subject to verify this. The information can be taken on board or ignored as is desired. At the end of the day, I am ONLY ABOUT HELPING PEOPLE. I hope this is understood

[Geoff]

Hi Peter,

I don't think anyone doubts your intentions. However, as moderators we try to maintain an atmosphere that encourages input from everyone, regardless of their experience, ability or knowledge. We have seen other forums implode or fade away because a few probably well-intentioned individuals who 'knew they were right' and 'had the facts' have intimidated - however unintentionally - those who were already shy of putting fingers to keyboard.

Everyone's input is wanted, but we want to guard against anyone feeling disparaged because they have different viewpoints. The idea of this forum is to add to the pleasure of sailing an Investigator. It is not meant to be a definitive rulebook for the class. Let's try to keep it light, open and encouraging.

[Peter T]

If anyone out there needs help with anything with their boat, feel free to PM me and I will be more than happy to assist in any way I can privately

[Andrew]

Thanks for the info I’d say I won’t be covering it up. I just wondering as I thought it could of made fixing the keel a bit cheaper and quicker but if it’ll sacrifice performance I won’t be covering it up.
I think in the next few weeks I’ll be setting up something to get the boat off the trailer and up high enough to do repairs. Where would the best spot be for the straps holding the boat up to be. Or can they sit anywhere

Hi Kieran,

Here's a link to my blog, details how my boat was blocked up safeley in a bush pole shed with deco floor.

http://teria563.blogspot.com/2014/01/tr ... l.html?m=0

Everyone's situation for boat maintenance is totally different, as are the tools at hand. I used car jacks and car stands on wood pads, to hold the weight of the keel. But also put a 44 gal drum and steel workhorse (with padding) under ends. Sideways movement was prevented by wood legs off gunwales and 1/2" ropes from strongpoints to shed frame.

There's other methods. Some more advanced like Peters lifting frame. Some simpler than mine, such as laying the hull on its bilge in lawn backyard with the keel up on wood blocks first (also requires plenty of mates muscle).

https://m.facebook.com/groups/840471046 ... &__tn__=-R