Why are GP 14's so fast?

Many things in sailing leave me confused. One of them is sailing in light winds, below say 5 kts. Our Taser weighs 68 kilos and we are quite light. The Taser carries 11.43 sq m. A GP14 weighs in at 133 kilos and carries 12.85 sq m. plus a small kite 8.4 sq m. The extra sail area on the GP is presumably taken up by the genoa. Until there is sufficient wind for us to both sit on the same side and make the rig operate efficiently we have trouble getting away from a well sailed GP much less perform to our PY. I did wonder if wetted area could have somthing to do with it, a Tasar is wider and longer but a GP sits in the water like a barge and has two horrible rubbing strakes moulded into the bottom chines. The situation is even worse with a Laser 2 which sticks like hell in the light with 11.52 sq m and 80 kilos. It seems that whatever you do those old GP's keep on trundling along. All this changes dramaticaly when the wind gets to 12 kts but it is still frustrating in light stuff. Tasar PY is 1026, Laser 2 1035 and GP1147!!
We do accelerate better in little puffs but it just is'nt enough. Any technichal explanations?

i seem to recall that overlapping genoas make a big difference in light airs, something about accelerating the flow through the slot, think ac flaps and slats on approach.

Combination of momentum and hull & foil shape.

The GP goes well in light stuff, Enterprises even more so. If you look at the hull shape, there's a lot of freeboard and the stern of the boat is not designed around getting the boat planing early.

As a result, in light winds, it is much much easier to get the transom out of the water, which reduces drag massively. Secondly their weight counts in their fvour as they don't decelerate as readily as yout Taser.

Foil shape makes a big difference too - the GP & Ent have relatively short centreboards with a long cord, which gives them a lot of lift at low speed. Your Tasar I suspect will have much longer, narrower foils, which will do absolutely sod all until you get moving above 2-3 knots, at which point they lift like hell.

The trick is to get the stern out of the water and eliminate drag. GP's are utter bandits on handicap though.

Boats with lots of rocker go well in light winds. They can reduce wetted surface, tack easily and generally react better to what goes on around them. Also, soft sails are more easily read. I'd not have said that the GPs were anything like the best in those conditions, though. Round bottomed 2 sail boats (see that thread!) tend to be much happier.

Originally posted by Stefan Lloyd Originally posted by fizzicist Secondly their weight counts in their fvour as they don't decelerate as readily as yout Taser. Or accelerate either. So that isn't the explanation. Your argument about lifting the stern is the same as mine: reducing wetted area is especially important at low speed.

 

You tend to find that when it's light, there's lots of little zephrys and gusts - the heavy boats do well because they have the momentum which carries them into the next gust. The other problem very light boats like the Tasar have is that they have a habit of accelerating out of the front of the gust & the slower boats sit in it longer.

The argument about boats with lots of rocker is more powerful though - look how well a phantom goes in light winds & look how easy it is to get the stern lifted on those.