10kn ! Can this Be True ?!

[thomm225]

We used to hit 10 knots pretty easily on the Soverel 30 I used to crew on back in the mid 1990's.

The Skipper would point out the speed to me, but it really didn't mean much at the time since the day before when I was racing on my boat I was hitting speeds in the mid 20's

[wingssail]

Originally Posted by thomm225

We used to hit 10 knots pretty easily on the Soverel 30 I used to crew on back in the mid 1990's.

The Skipper would point out the speed to me, but it really didn't mean much at the time since the day before when I was racing on my boat I was hitting speeds in the mid 20's

Thomm, in the 1990's that was probably a Soveral 30 IOR race boat, (not the previous version from the 60's). In either case that is a lot of speed for a 30 boat. So if you guys hit 20 knots pretty easily then more credit to you all, crew included, for being able to do it.

And note: both versions had fin keels and either spade rudder or skeg rudder, well aft of the keel.

[wingssail]

And finally, here is my all time favorite sailing video, a planning boat going really fast, then speeding up dramatically!

Watch the jibe right at the beginning, then how powerful the rudder controls the boat, then watch the phenomenal acceleration.

Don't both with the upwind stuff later, it's boring to me.

https://www.youtube.com/watch?v=beRVIHhAERc

[Jim Cate]

Nice footage, Fred, but if you look at how fast folks seem to move in the cockpit, I'd have to guess that it is sped up quite a bit. Seems a shabby trick from Quantum...

Jim

[wingssail]

Originally Posted by Jim Cate

Nice footage, Fred, but if you look at how fast folks seem to move in the cockpit, I'd have to guess that it is sped up quite a bit. Seems a shabby trick from Quantum...

Jim

NOOO! I don't believe it, It looks natural to me. Can't be, I've been watching this video for years and now you try to break my heart!

Anyhow, the guys in the back don't look jerky, but most of all, the water the splashed in the front and the water flowing back through the cockpit, doesn't look unnatural, so just go back to Tazzi and be quiet and leave me with my fantasy.

[Jim Cate]

Originally Posted by wingssail

NOOO! I don't believe it, It looks natural to me. Can't be, I've been watching this video for years and now you try to break my heart!

Anyhow, the guys in the back don't look jerky, but most of all, the water the splashed in the front and the water flowing back through the cockpit, doesn't look unnatural, so just go back to Tazzi and be quiet and leave me with my fantasy.

Fred, maybe because life goes so slowly down here in Tassie the video looks unnatural to me.

And BTW, they don't appear to be gaining on the boats ahead of them...

But that flat wake and clean separation at the stern are sure cool!

Jim

[newhaul]

Originally Posted by Jim Cate

Fred, maybe because life goes so slowly down here in Tassie the video looks unnatural to me.

And BTW, they don't appear to be gaining on the boats ahead of them...

But that flat wake and clean separation at the stern are sure cool!

Jim

Looks legit to me one little question how big is rhat boat and what is the draft of rhe actual hull ? And is it a wing keel?

[wingssail]

Originally Posted by newhaul

Looks legit to me one little question how big is rhat boat and what is the draft of the actual hull ? And is it a wing keel?

That is a TP 52. The hull itself, while floating at the dock, is probably about 2-3 feet maybe less, but I haven't been able to find out the value, exactly. The keel is a straight fin with a bulb at the bottom 3.85 meters.

This is a more recent Quantum, 2018 by Botin Partners. Doug DeVos of Amway fame is the owner, and wife Betsy is US Education Secretary. The tactician of this boat, for years, has been Terry Hutchinson who is now a key member of the American Magic America's Cup Team.

I've always fantasized about turning one of these boats into a cruiser, but the inside is just impossible.

[seandepagnier]

I have reached speeds over ground above 10 knots in cook strait, agulhas current, and even 12 knots in lombok strait beating on 3rd reef with 40% headsail.

[wingssail]

Originally Posted by seandepagnier

I have reached speeds over ground above 10 knots in cook strait, agulhas current, and even 12 knots in lombok strait beating on 3rd reef with 40% headsail.

Those SOG's are good speeds. I have seen 4.0 knots on the East Coast of Africa (Agulhas) and I know that Lombok Straits has similar currents however the Cook Straits has currents which exceed 7 knots. So SOG's can be higher or lower than the boat speeds, some times by quite a bit.

[Knotical]

Nice beam or broad reach with a little help from the sea and current - yes, it's possible to exceed theoretical hull speed. We frequently do 8-8.5 kts in perfect conditions with current only adding half a knot (typical in western LIS), the boat's hull speed is 7.

Transiting East river we have hit speeds of 11+ kts, with current doing most of the work.

[newhaul]

One thing to remember everyone is that hull speed is a derivative of waterline length which changes as you heel over getting longer .

A 20 to 25 degree heel is optimal for most monohull sailboats

[Adelie]

I’ve been on a Cal40 surfing at 14kt. The skipper told me they hit 23kt surfing the Tranpac in the 1970s.

The difference between a displacement hull and a planing hull is not a clean line with obvious differences. There is a spectrum of hulls in between.

[Jim Cate]

Nice beam or broad reach with a little help from the sea and current - yes, it's possible to exceed theoretical hull speed.

Please, guys... when discussing hull speeds, speed over the ground, as measured by GPS, is meaningless. Only speed through the water is of interest. Current does not enter into the picture, either for or against.

Jim

[Don C L]

Originally Posted by Jim Cate

Please, guys... when discussing hull speeds, speed over the ground, as measured by GPS, is meaningless. Only speed through the water is of interest. Current does not enter into the picture, either for or against.

Jim

Killjoy!