Pointing

A question for those in the know!

What affects the ability of a dinghy to point well when on a beat?

Originally posted by Sumo A question for those in the know! What affects the ability of a dinghy to point well when on a beat?

A whole host of complicated stuff:-
The major factors:-

drag, hull and rig
rig layout and sail design
foil design

There are two major limiting factors
- how close you can sail to the wind and still have the sails fill
- how much slower you get as you get close to the wind.


One of the subtler factors is that the faster you go the lower you point.

I remember sailing a Cherub a few years ago which had a 6 ft long by 9 inch board.  It never got up to the mark in the lulls, but in the puffs it went like the proverbial and if it persisted I always ended up overstanding!

But the previous replies are right, its down to good sails and a good set of foils and a hull which doesn't cause too much drag and (this is often forgotten) a rig which doesn't cause to much drag.

But I have seen many a novice blame his boat for not pointing, whereas in fact he was on the wrong wind shift.  Here's a simple explanation for those prepared to get the graph paper out and work out the subtleties.  When you are being lifted your boat feels like its outpointing those ahead and when you are headed you can convince yourself your boat is not pointing.  But if you look over your shoulder the truth will be revealed!

Pointing ability is, like all tuning issues, dependant on the interaction of a huge number of factors.

Mainsail leech tension has already been mentioned. On a boat like my FD, with a centre main and traveller, this is controlled in moderate breezes by mainsheet tension. As you wind on the leech tension, you also straighten the genoa luff - good thing, also aids pointing. However, as mainsail leech tension increases, you also pull the mast aft from the hounds upwards. This will free the genoa luff and widen the slot - bad thing, hurts pointing. In an FD which will plane to windward in 10 knots, pointing is crucial as the boat can feel great sailed free, but you can find yourself reaching around the ocean, going warp factor 9 but travelling 10 times further than anyone else! This is often simply due to the leeches being too soft. Tighten the leeches and what happens? You're overpowered, main is backwinded by the huge genoa, boat is slow and therefore the foils dont work as well. You're pointing in the right direction now, but slower than a slug on crutches and making a ton of leeway!

What I'm trying to say, in a longwinded and roundabout way, is the whole thing is a balancing act. If your boat doesn't point, first thing to check is the nut on the end of the tiller!

Neil

Good points well made Rick. In an ideal world your boat should be tuned so that you have an upwind 'groove' between pointing as high as possible and footing off by (probably) no more than 5 degrees. You can then go 'bow up', for example off the start to clear a boat to leeward, then once you're clear drop the bow for speed to get over the boat to leeward. Rick is absolutely right, if the boat's not flat there's no point in worrying about any tuning or trimming issues, cos you won't point anyway! In light airs, pull the sheets on slightly in the puffs, otherwise the extra force of the breeze will just open the leeches more. In strong breezes, I tend to luff AND ease the main (both hands down) to keep the boat on it's feet, then drop the bow back down before the main comes back in. It is a matter of what suits you, but the vital thing is to keep the boat flat and moving. That way the foils do the best job of limiting leeway