Centre board use

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Watto
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Joined: Tue Jan 19, 2021 7:45 pm
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Centre board use

Post by Watto »

So I typically drop the center board as long I know I’m deep enough and raise it when I’m coming into shallows but this has me thinking.

Should I be raising or adjusting depending whether I’m coming down wind or another angle.

Open to advice.
Luke

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Fathom
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Peter T
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Re: Centre board use

Post by Peter T »

Hi Luke. The tiller should tell you mate. Pulling the centreboard up a bit obviously moves it towards the stern as it is folding up which will move your "CLR" ( centre of Lateral resistance) aft. The balance of the boat is a relationship between the CLR and the centre of effort of your sail area. Slightly pulling the board up can overcome weather helm or a heavy tiller. Its a bit of a balancing act. If you have less centreboard you will get more slip sideways and so will not point as high as if you have it fully lowered.
Down wind it is less important to have as much centreboard down.
What I suggest is that you play with it and find the points of sail that is comfortable without too much weather helm
.
In saying all this, the Investigator is a very well designed yacht but there would be no problem playing with your centreboard position to learn what it does to speed, comfort and handling.
Hope this is of some help Luke. Cheers
Regards Peter T
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Ozzie
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Re: Centre board use

Post by Ozzie »

As a rule of thumb I usually leave the cb down unless I’m doing a long run down the lake . In my case it’s more because if I’m adjusting it up and down I get relaxed and forget and attempt to sail into the wind with it up, usually in restricted space to get back to the mooring. Suddenly I realise I’m making leeway :oops: I’m not aware of much weather helm on a reach so it stays down but Peter’s post is a good summary of what to look for.

In the early days before I had set the furler up properly I would cleat the jib halyard at the cb cleat to remind me to drop it after passing the shoals near the mooring and reverse the procedure coming back.
Ozzie
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Greg
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Re: Centre board use

Post by Greg »

Peter T wrote: Fri Dec 31, 2021 4:38 pm Hi Luke. The tiller should tell you mate. Pulling the centreboard up a bit obviously moves it towards the stern as it is folding up which will move your "CLR" ( centre of Lateral resistance) aft. The balance of the boat is a relationship between the CLR and the centre of effort of your sail area. Slightly pulling the board up can overcome weather helm or a heavy tiller. Its a bit of a balancing act. If you have less centreboard you will get more slip sideways and so will not point as high as if you have it fully lowered.
Down wind it is less important to have as much centreboard down.
What I suggest is that you play with it and find the points of sail that is comfortable without too much weather helm
.
In saying all this, the Investigator is a very well designed yacht but there would be no problem playing with your centreboard position to learn what it does to speed, comfort and handling.
Hope this is of some help Luke. Cheers
Generally when it’s very light I leave the board up. I’ve played around with the angle a lot and I’ve put a mark on the lift rope where (roughly) I’ve found the best balance for helm and pointing on my boat. I can pretty much steer with my pinky finger into lifts in 10-15kts but that also relies heavily on who is doing the trimming on the jib. Every boat/crew will be different, play around with it and make sure you have a sharpy in your pocket to mark the lift rope when you find a good spot.
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Andrew
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Re: Centre board use

Post by Andrew »

Hope the New Years good,

This is how i operate my centreboard,

Like you my default is to lower it when leaving the dock, and leave it down if too much else is happening.

Once settled in on course..
  • When running downwind in the light i haul it right up, which gives a bit more speed. But when running or broad-reaching with following seas i put it about 1/4 down, so it acts a bit like a surfboards skeg and makes it easier to steer straighter in these conditions.
  • When reaching or close-reaching adjust the centre-board rope (and sails sheets) until the helm balances up nicely.
  • When in shallow waters - it's 100% down on any point of sail (or motoring) - It becomes a good early warning system which helps prevent the main keel grounding.
    (but don't forget it when heading for the ramp)
Hope this helps, but of course everyone has a system that works best for them. Investigators can still sail quite well with the board up at anytime so they're a bit more more forgiving on leeway than the standard "dinghy hulled" TS with its board up.
Andrew

Investigator #9 Teria
Watto
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Re: Centre board use

Post by Watto »

Andrew,

Interesting you leave it down in shallows as a warning system.

What does it sound feel etc when it touches the bottom and hopefully swings back?
Luke

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Fathom
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Andrew
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Re: Centre board use

Post by Andrew »

Gday Luke,
Mud is hardest to hear, but acts as a bit of a brake , reducing boat speed gives it away.

Sand and shells scrape louder.

Coral rubble is the most "alarming", bounces over but makes for quicker evasive action.!

The board always swings back ok as designed, and no damage done. Just after it hits, i grab the lift rope and use it to "feel" for the depth under keel, pull the plate up a little so it clears, cleat it off there and escape the grounding zone. (Often a river mud or sand bank)

The hot dip galvanizing seems to take it well, Better than the fiberglass keel would. Lucky these are rare events, more common in new waters.

Fitted a fish finder after the last trip so won't have to rely on the centerboard warning system as much from now on.
Andrew

Investigator #9 Teria
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