Is it a disadvantage to have a boom pocket on the sail? Saw an older sail today with this feature but wonder about lack of adjustment to 'belly' the sail, especially in light wind.
All the yachts I have seen have loose footed sails and adjustable outhauls at the
clew to shape the sail except for the very simple yachts
I use this feature a lot when sailing and imagine it would be quite a disadvantage
not to be able to do this for a racing yacht
I would like to fit this arrangement on my mini some time
Another question in the same area, the pros and cons of a floating boom. All aus yachts apear to favour a rowlock, but the kiwies and european class5 seem to prefer a floating boom.
cheers
aus230
As you say the preference here is for the floating boom
Not sure of the pros and cons but it is simpler
Ohope beach looking its best Hope to give it another workout tomorrow
from a class 5 point of view a boom pocket laid flat measures say 1600mm x120mm=0.192 msq. that you have lost as doubled up sail area.
I did notice in Jan just how much the leading club 88s were letting out the foot- up to 250mm on the upwind legs where the wind was iffy.
the theory in the eighties was that you had a flexible boom which bent and flattened the sail as you sheeted in.
Ive always been disapointed with the floating boom, particularly upwind IF you dont have the sheeting JUST right. I prefer to have a rowlock loosly tied and only touching the mast on its sides when sheeted. this allows you to pull the boom back and off the mast so you can push it forward on the lee side to make a full sail for starting
Sailing around today I realised another good reason not to have a boom pocket
I often lift the foot to peer out to leeward ![ on the mini]
Cheers Hiko
The original idea of the floating boom was that you adjust it down to the leeward side with your non sheeting hand ALL THE TIME. This then was a constant adjustment, braced your hand over the top of your helmet, and changed hands each time you tacked.
The original rules for Class 5 specified that the mast and the boom be located by means of "a pocket on the luff for the mast, and a pocket on the foot for the boom" so you had no option.
Foot adjustment is an area of constant discussion with proponents and oponents!
The boom should not be able to be sheeted that low if you read the rules!
Promos have a rule regarding the boom being above the head , and that it must extend behind the head.
for class 5 , the lowest point of the boom must never come below
-45cm from the ground
-eye level
whichever is the highest.there must be a device that makes it impossible to sheet any part of the boom below this level.
so part of the challenge in designing your yacht is to get your eyes below 45cm, then bring your boom down to your eyes.
it can be tricky
and when you do , you can bet there will be somebody with a tape measure checking you 
.
I dont recall any such life complicating rule for the lefroy mini
and when you do , you can bet there will be somebody with a tape measure checking you .
OOps , sorry , edited in the original post.
cheers , Mr Paul"The landyacht" Day.
of the landyachting Days.
On another topic while we are in this area. I noticed from some NZ pics and some from argentina that some yachts where using lead weights behind the front wheel. How much of a benifit is this (I imagine it is for stronger winds)
Cheers
aus230
The weights behind the front wheel was to maintain as per the rules a minimum of i think 5 kilos on the front wheel. Due to the design of the yachts that we hired, i was unable to sit far enough forward to maintain that 5 kilos and have straight knees( another rule) so i had to tape coke bottle full of sand behind front wheel. This prevented me from moving my weight centre around. If i slid forward the weight would increase too much and if i slid back the weight stayed on the front wheel, a big disadvantage.
the promo class has a minimum weight over the front wheel, which was checked on a set of bathroom scales, with the pilot laying in the yacht, legs straight sail fully sheeted. from memory it was 10.5kg?
if you were a tall pilot this became a problem as the seat left you way back in the yacht. Tp1 had to pile heaps of wet sand onto the front end of his rental yacht. the seagull yachts actually had a couple of nuts welded on to take indivually cast lead weights to suit each pilot
in a strong wind the tall narrow sails need lots of sheeting and careful balancing to ensure that the tip of the sail doesnt start to flap. On the upwind leg , or when tacking , a couple of flaps quickly translates to the front wheel bouncing , or even lifting off completely..
this happened to me once in Argentina , I almost landed the front wheel on top of a shiney Hilux 4x4. when I got caught in a willy willy whilst in a tacking duel with a full on class 5 around the upwind mark.
We were both impressed with surviving
the tackas the background breeze was just on 25knts with blowing sand.
When testing my new 5 I would go out to the claypan on really windy days and try to replicate the conditions, then alter mast step position, bodyweight location, sheeting postion, upper mast stiffness,etc, till I got it to stop. I even recut the luff of the sail twice to stop the dreaded flapping.
BUT that gave me a class 5 that scares me at just how controllable it is in a blow , but its sadly bad in very light downwind condition , but Im working on that
I think this post has been interesting , I have another question.
What is the benifit of a centre pull boom compared to a rear and front pulled attachment. I have asked these questions mainly for new comers to the sport to see the different options and why the changes have been made.
Cheers
aus230
I think Clemco covered this further up in this post I cant add anything much to what he has written Hard to have it in a mini yacht though due to the pilot
being more forward relative to the sail comparing it with a class 5
Clem seems to have managed it but the foot of his sail is very short
That sail would be too small for my weight I think
Cheers Hiko
) and pulls the roach tighter, which may be better in very even wind conditions, as well as the ease of it's physical location. The "whip" on a Blokart does some of the same self correcting.
I find that with the rear sheeting combined with down haul more space is available for body shifting of weight centre to keep windward wheel down.
On the other hand centre sheeted booms can be physically pushed/pulled to windward allowing you to point closer upwind. I used this to good effect in argentina when rounding the bottom marker to aleviate the tendency of the yacht to become air borne.
I also pull or push the boom to effectively aero brake or control the sail around markers on Lefroy. I do this with the sheet slightly slack as I can stop the more violent sail position changes when turning in higher winds.
1 Thing I forgot to mention you need good upper body strength to man handle the centre sheeted boom[}:)]
[}:)]
A great pic..... the sail shape looks good in the pic.
If you don't hang onto the boom what is the sail shape like then?
The pic Hiko posted on 25/04/2010 in this thread looks like the sail is being pushed to windward.
what i ment was .... what would the shape be if the pilot of NZ717 let go of his boom, would his sail go to windward?
you can see perfectly , just like the rest of us
