Thread: GIS X or Raid Special

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Can you tell I write instructions for a living?

Catchya
MIK

Go

I happened across a thread over on the other forum that Brian (keyhavenpotterer) started a while ago titled of all things

"Chined plywood mini transat by Lucas"

hmmmm..........great minds think alike or perhaps fools never differ not sure anyway some really great discussion and thinking, a top read.

will have a peek

Mik,
Gavin posted this article about the Uffa Fox airborne lifeboat and I couldn't help think the hull form is so similar to the way the thinking is headed in so many areas.

Some interesting history in the other links as well.

An airborne lifeboat on the Isle of Man | intheboatshed.net

Howdy Mike,

One thing that was quite interesting in the USA was sailing Dave Graybeal's Goat against a Core sound 18 (I think??).

The core sound is thoroughly a trailer boat. Really has to be winched on and off the trailer. That bit of extra length and beam really makes a much bigger boat.

It is a smart sailor two, but it didn't have the legs of the Goat in a moderate puffy breeze. Maybe 9 to 14 knots. Upwind and down it couldn't match.me in the Goat. I was trying mind you - but the weight and size of the coresound's rig doesn't give the sensitivity to every puff like you get with the goat.

Also think of how the Goat went in the Caledonia raid. Third in all the rowing legs with only one person rowing and did pretty well on the sailing side too, maintaining close to the same placing.

Also look at the Texas 200, The 15ft 6: goat was in there with much bigger boats. Sea Pearls are 19 and the Lagunas are 23.

And the Goat was up there reasonably well.

As the boat gets bigger it loses efficiency.

Bigger boats might be the way people are going, but I am not sure it is justified.

Wonder how much sailing the lagunas have done since? John has done a whole lot of other sailing in his GIS, not to mention rowing quickish sorts of rivers.

A whole heap of use.

The final thing is that the Lagunas were designed and I think three or four were built. Wonder how much the plans are? Plans are $50, so they have their value in promotion (and fun) rather than the hard earned!

I think there is some sort of approach here in this discussion, but I don't think bigger is necessarily it. So I am trying to think what WOULD work retaining the simplicity and general usefulness.

MIK

Originally Posted by Boatmik

Howdy Mike,

One thing that was quite interesting in the USA was sailing Dave Graybeal's Goat against a Core sound 18 (I think??).

The core sound is thoroughly a trailer boat. Really has to be winched on and off the trailer. That bit of extra length and beam really makes a much bigger boat.

It is a smart sailor two, but it didn't have the legs of the Goat in a moderate puffy breeze. Maybe 9 to 14 knots. Upwind and down it couldn't match.me in the Goat. I was trying mind you - but the weight and size of the coresound's rig doesn't give the sensitivity to every puff like you get with the goat.

MIK

Hey MIK,
I realize it's been a while since the USA fun tour but if you'd be so kind as to put on your 'remembering' cap for a minute... what was the rig on that boat you were referring to (above)???
The Coresound 15, 17, & 20 are designed to be cat ketch rigged.
Maybe it was another design.
Thx for any clarification if you can,

Tom,

I'm not Mik but I have sailed with him (that rudder failure was not my fault - wasn't Mik's fault either ) and can answer your question.

It was a Core Sound 17 rigged as designed as a cat ketch.

Originally Posted by BobWes

Tom,

I'm not Mik but I have sailed with him (that rudder failure was not my fault - wasn't Mik's fault either ) and can answer your question.

It was a Core Sound 17 rigged as designed as a cat ketch.

I'm not meaning any disrespect of the Coresound, it is a great and very quick boat. I am suspecting that a bigger GIS would start to have the same sailing characteristic.

MIK

Originally Posted by Boatmik

Bigger boats might be the way people are going, but I am not sure it is justified.

Wonder how much sailing the lagunas have done since? John has done a whole lot of other sailing in his GIS, not to mention rowing quickish sorts of rivers.

A whole heap of use.

I think there is some sort of approach here in this discussion, but I don't think bigger is necessarily it. So I am trying to think what WOULD work retaining the simplicity and general usefulness.

MIK

Mik I think from the outset my thoughts for a performance boat has been leaning towards something around 20' with three crew, in fact a whole different can of worms than the GIS. Whereas I believe most would lean towards a modified GIS perhaps with just shade more length incorporating the ideas from Joost, Clint and John for all the reasons you explain.

Certainly John and Joost have demonstrated what a great boat the GIS already is and maybe this discussion just confirms it already ticks the boxes for the majority.

Cheers
Mike

Originally Posted by Boatmik

I'm not meaning any disrespect of the Coresound, it is a great and very quick boat. I am suspecting that a bigger GIS would start to have the same sailing characteristic.

MIK

Come on MIK, the Coresound is a TUB for geriatric sailors!

Whoops, this almost applies to me

Just out of curiosity, what would 15-20kg of lead in the bottom of a longer (2.0m?) hardwood centreboard do to the cruising abilities of a boat like the GIS or a narrower longer sailing canoe type boat?

20kg of lead is just cutting a 300x300 mm square hole in the lower part of a 22mm thick centreboard and pouring it full of lead before glassing the whole thing.

My GIS with carbon mast will have a total weight aloft of only about 5 kg with a COG of about 2 metres above the gunwales, it wouldn't take much weight at the bottom of the centreboard (1.5 m below the gunwale?) to give a positive righting moment all the way to 90 degrees.

Ian

I've been wondering the same thing. Not sure about all of the ramifications but one limitation on an open boat is the angle of heel at which the gunwhale goes under water. I would imagine the loss of buoyancy at that point causes all kinds of trouble that the righting arm of the keel cannot overcome

Originally Posted by SimonLew

I've been wondering the same thing. Not sure about all of the ramifications but one limitation on an open boat is the angle of heel at which the gunwhale goes under water. I would imagine the loss of buoyancy at that point causes all kinds of trouble that the righting arm of the keel cannot overcome

Yes, but one thing the GIS has is high sides, and a flat bottom, so I guess it can go a long way before the gunwale goes under.

Problem with a boat with a flat bottom and high sides is that the high sides force the crew weight towards the centre line more quickly as you go over, so although it has high initial stability, it reaches a point where it suddenly looses all stability. You are right, any centreboard weight would have to kick in it's righting moment before you reached the point at which stability from the form and crew weight disappears.

Not something I'm thinking of for general off the beach sailing, but I have ambitions to do some more extensive camp cruising. I'd initially thought of the GIS as a 'first boat'. Learn from the experience and see about a ... (where was I?)... a bigger boat depending on what I learn from the GIS/how many of the (at present young) family are into it. But - if I can make the Goat do everything I want, with a bit of tinkering, then that would be even better. I share (Bolger's, I think, and paraphrasing), the opinion that a boat should either be light enough for the crew to carry up a rocky beach or blue water cruising capable.

Ian

Ian

Originally Posted by SimonLew

I've been wondering the same thing. Not sure about all of the ramifications but one limitation on an open boat is the angle of heel at which the gunwhale goes under water. I would imagine the loss of buoyancy at that point causes all kinds of trouble that the righting arm of the keel cannot overcome

I imagine 20kg of lead so far down would make for a very stable GIS. The dam where I sail hosts a Sailability contingent. They use mainly Access 303s and Access 2.3s, a feature of which is lead weighted daggerboard. Basically, those kids are as safe as houses in those boats in all kinds of conditions, with no where near 20kg of lead. By the way, they only carry about 50sf of sail.

The only doubts I would have about taking the GIS sea cruising (I mean outside the harbour) has to do what Simon alluded to. Because there are no side decks, I'd worry about the gunwale going under. Bay, river and estuary cruising...no problem. However, others have done coastal cruising without mishap.