Effect of weight on boat speed

We/I found volume which you lot call displacement has a more beneficial effect, the greater the volume the less weight has any effect. Take your Streaker I've noticed with only casual observation that some of them appear to have more volume, especially the plastic ones, notably one that appeared down our lake made by Boatyards at Beer I think, it sits noticeably higher in the water than a wooden one and is quicker. Someone did explain to me what they'd done but I wasn't that interested tbh.

So, helm weight variations in a Laser for instance will have more effect than they would on say a Solution, and I'd guess the Aero wouldn't be as weight sensitive as say the D Zero, the former being a higher volume than the latter to casual observation.

So helm weights in a wooden streaker would be worse than in a plastic one from that Boatyard at Beer outfit, the more so because a streake is underpowered with a small sail.

My other pet rule of thumb sail square mete per ten kilos of helm weight, so a streaker with only six square metres suits a sixty kilo helm, a Solutions 8.5 suits an 85 kilo helm a Laser 7 equals seventy kilo etc. Either side of that will inevitably penalise in the wrong condition. Light helms in strong wind and heavier helms in lighter conditions.

Finally all of this is more acute on fresh water than it is on the sea.

Originally posted by iGRF We/I found volume which you lot call displacement has a more beneficial effect, the greater the volume the less weight has any effect. Take your Streaker I've noticed with only casual observation that some of them appear to have more volume, especially the plastic ones, notably one that appeared down our lake made by Boatyards at Beer I think, it sits noticeably higher in the water than a wooden one and is quicker. Someone did explain to me what they'd done but I wasn't that interested tbh. So, helm weight variations in a Laser for instance will have more effect than they would on say a Solution, and I'd guess the Aero wouldn't be as weight sensitive as say the D Zero, the former being a higher volume than the latter to casual observation. So helm weights in a wooden streaker would be worse than in a plastic one from that Boatyard at Beer outfit, the more so because a streake is underpowered with a small sail. My other pet rule of thumb sail square mete per ten kilos of helm weight, so a streaker with only six square metres suits a sixty kilo helm, a Solutions 8.5 suits an 85 kilo helm a Laser 7 equals seventy kilo etc. Either side of that will inevitably penalise in the wrong condition. Light helms in strong wind and heavier helms in lighter conditions. Finally all of this is more acute on fresh water than it is on the sea.

Originally posted by RS400atC Bethwaite's book has some speed/drag graphs for some hulls ballasted to various all up weights. If you extrapolate from that, it does not take a huge amount of excess weight to lose that vital half boat length in a one-design drag race. And that is on flat water.

You may not have noticed that this is a 17 month old thread?

Edited by Sam.Spoons - 24 Oct 20 at 3:34pm