Thread: GIS X or Raid Special

Just to be clear, is this thread about mods to existing Goat for Raiding, or are we talking about Big Goat, self draining the works,



Experience from RAID41 made us realise that the self draining floor adds a lot of work.

Brian

Originally Posted by keyhavenpotter

Just to be clear, is this thread about mods to existing Goat for Raiding, or are we talking about Big Goat, self draining the works,



Experience from RAID41 made us realise that the self draining floor adds a lot of work.

Brian

Brian at this early stage it could be either however I am thinking self draining is almost a must for safety and competitiveness. The report from Joost suggests more length plus two rowing stations important for Raiding.

Thanks for the drawing for some reason I could not find a post of a long GIS.

Cheers

Howdy,

My concerns are

1/ it is a really big boat ... hard for two people to move on shore - might be hard to hold upright when the wind gets up or hard to right from capsize. Move the crew up to three and you have to find that extra person all the time. Singlehanding will be out or tricky
2/ more wetted surface than the Goat
3/ a little bit more potential speed

I am not trying to stop this but am thinking how to make it work - find the optimum.

One thing was how they handicap the events for different size boats too. That should be part of the analysis.

Also the question is ... is it better to make a boat that will really win, or allow more people to participate. Not everyone can build an Oughtred, but everyone can build a Storer.

Wonder what boats have been consistently good performers in RAIDs. Not the big skiff type boats ... but the Oughtreds and other sensible boats that get speed from refinement.

MIK

Can anyone put the Ness Boat dimensions weight and sail area down here?

I assume you mean Iain Oughtred's Ness Yawl?

Length Beam Draft Weight (kg) Sail Area
19' 2" - 5.84m 5' 3" - 1.60m - 130 133 sq ft - 12.35 sq m

Didn't give the displacement.

The Ness Boat has been renamed 'Tirrik' - dimensions are:

Length 16' 10"
Beam 5' 4"
Weight 95Kg
Sail Area 108sq ft

http://www.classicmarine.co.uk/details.asp?Name=Tirrik

The Ness Yawl is bigger - 19' 2" x 5'3", 130Kg, 102 - 133sq ft (lug or sloop)

http://www.jordanboats.co.uk/JB/Iain...ess%20Yawl.pdf

The two main Oughtred boats which are involved in Raids are the bigger Caledonia Yawl and the super slim flyer, JII now called Arctic Tern.

http://jordanboats.co.uk/JB/IainO_Ca...%20&%20JII.pdf

http://jordanboats.co.uk/JB/IainO_Ca...nia%20Yawl.pdf

http://jordanboats.co.uk/JB/IainO_Ca...ess%20Yawl.pdf

It feels to me that just optimising the two person rowing for Goat might be most fun and help most people. None of my business though!!

Brian

Picking up Brian's point, a GIS optimised for rowing is one (relatively small) adaptation (GIS X). Another moremajor exercise is to design Raid42. Both are valid design exercises, but we should make it clear to Mik what we are talking about! Both interest me, but I suspect I would build GIS or GIS X ahead of Raid42

Brian's advice makes a lot of sense to me too! I do think however that side by side rowing with a crew of 2 is not the most efficient way to propel a boat; more power can be translated to the water when rowing in tandem formation with each of the crew members handling 2 oars. This would however require an additional thwart to enable easy rowing and transitioning from sailing to rowing, something that might be difficult to incorporate in the GIS.

3 very successful participants the fast few years in both the Finland and Caledonian raids (just mentioning boats crewed best by 2 persons, and not at really specialized boats) have been:

1. Iain Oughtred;
- the Ness Yawl (loa 5,84 width 1,60, 11.25m2 and 130 kg)
- Jeany II/Artic Tern (loa 4.52, width 1.64, 11.15 m2, 110 kg).

The Ness boat has indeed been redesigned and renamed Tirrik (smaller boat as Clarkey has pointed out at loa 5.13, width 1,64, 10 m2 and 95 kg). The Caledonian Yawl is really massive and is a bit much to row with a crew of two (better rowed with 4 rowing 2 a side handling 4 oars). The other Oughtred boats seem to be really nice and quite fast to row with a crew of 2 sitting behind each other and handling 4 oars.

2. The Arend Lambrechtsen designed Silent Nell has won Raid Caledonia: loa 5.00, width 1.70, draft 0.20/0.85, 8 m2 balanded lug rig, 200 kg.

http://www.destilleboot.nl/boten/sil...ificaties.html

Please click "foto's" to see it in action (Dutch website only)

3. Le Seil 18 designed by Francois Vivier: loa 5.40, width 1.62, 11m2 and 270 kg

http://www.vivierboats.com/html/stoc..._oar.html#seil

I do seem to be thinking along different lines than our dear friend Mike:

- In my opinion a self draining cockpit is not required (please also see Brian's comments with regards to the self bailers). In a raid you don't really want to push it too far causing the boat to capsize anyway.
- Sleeping is normally done on shore, some storage room would however really be convenient (missing a bit on the GIS) to store some dry clothes, an anchor, some ropes etc. If more storage room is available, I prefer to bring a tent rather than sleep on the boat.
- An outboard well is not required for me (but I would like to the boat to row very well). If I do want to attach a motor to the boat, I prefer it at the back (no holes in my hull!).
- I am thinking of a slightly bigger GIS (GIS X seems to be a good name) with 2 thwarts but further much like the original: simple construction, classic lines. A smallish mizzen might be included (I have seen it is handy) but not really required for me -> I like simple and fast boats.
- The GIS's sailing qualities are fine as they are. For a raid type event however, some more oempff when rowing would be nice (will also keep the crew better occupied) and I feel that a GIS like boat would be able to keep up with the aforementioned successful raid boats when rowed by 2 persons rather than 1 person.

Next to this I do feel that it would be better to have a design that would allow more people to participate in Raid like events (bit more spacious and faster to row with a total crew of 2, maximum 3) than a specialist boast. Easy construction (like the GIS) would probably also make it more interesting from a commercial point of view as well, I think. No need to make a completely new instruction booklet.

Therefore, also taking into consideration the dimensions of the successful raid boats described above, I would like to introduce the following parameters for discussion:

- same hull shape and construction method as for the GIS. At the dimensions proposed below and with 6 mm plywood for the sides and maybe 8 mm for the bottom it will be very light (at least for the size)
- maybe 2 foat longer overall boat length when compared to the GIS (loa 5.40)
- 1.6 meter width
- same mainsail as on the GIS (around 9.5 m2). I believe it would provide sufficient power for the GIS X. Still thinking about the mizzen
- 2 rowing stations/thwarts allowing 2 persons to row the boat
- same dagger board and rudder system as on the GIS (dimensions should probably be similar as well)
- more onboard storage room

Nice discussion!

On the tandem (two rowers sculling) vs rowing (either tandem orside-by-side) issue, my very limited experience suggests that the issue resolves more to one of speed vs endurance. Sculling tends to be quicker but tire the oarsmen faster, rowing is a little slower (although you can get full force on one oar as opposed to splitting it between two oars) but you can last much longer. Rowing shells tend to be in a tandem configuration for drag reasons, not because side-by-side is less efficient mechanically. If you have the beam (which you will for sailing purposes) then there should be no diff in speed between tandem and side-by-side rowing.

The Swallow Boats have some great features, like self draining cockpits and can carry water ballast if needed, which can be filled and emptied on the fly. They are clearly pitched squarely at Raiders. The big downside in my opinion is the weight of them, but this is where these designers have made their compromise, and there are always compromises with any design. A slightly smaller and much lighter version of the Bay Raider would probably hit a sweet spot.

http://www.swallowboats.co.uk/compon...page/Itemid,1/

I think a mizzen for a Goat is a great idea.

https://www.woodworkforums.com/showth...t=78940&page=6

I think it is worth looking into a larger Goat, but from a designer's perspective we are changing some important things: weight, wetted surface area, etc. We often lengthen designs, but it is OK in round bilged boats. In skiffs you gain more wetted surface faster with great length due to the square shape.

To not bump up the sail area to accomodate for more wetted surface will decrease the Sail Area to Wetted Surface ration which is a measure of light air performance. OK for a sail-and-oar boat (because we'll often just row) but not OK for a one-design. So, to improve rowing performance we'd need to fine up the transom and reduce the planing surface a little bit. See, the reason the Goat rows so well is because it is small and light. Two rowers may be able to still power a bigger Goat, but all these things need to be looked at. Also, there will be more freeboard exposed for rowing in any wind. I am afraid the sailing qualities would have to be sacrificed a bit, and that may be hard for people to do.

Any idea is worth looking at, Michael may not have the time to look this hard, however! MIK, it must feel good to have people begging you for more!

Clint

Mik some delving questions, here are my thoughts

Originally Posted by Boatmik

1/ it is a really big boat ... hard for two people to move on shore - might be hard to hold upright when the wind gets up or hard to right from capsize. Move the crew up to three and you have to find that extra person all the time. Singlehanding will be out or tricky

Singlehanded not a critical element, assumed trailer launched and hard to move ashore.

2/ more wetted surface than the Goat
3/ a little bit more potential speed

Yes but with flatish aft sections an off wind flyer with some extra length for improved upwind speed.

One thing was how they handicap the events for different size boats too. That should be part of the analysis.

From my reading the Raid handicapping and class specs are somewhat loose the organisers appear to divide entrants based on length and performance from previous years. The main object being to participate and have fun and entrants should avoid being overly competitive.

Also the question is ... is it better to make a boat that will really win, or allow more people to participate.

My interpretation of a competitive boat is something with good hull speed over a wide variety of conditions so as not to be left behind by the bulk of the fleet not necessarily the fastest boat.

Not everyone can build an Oughtred, but everyone can build a Storer.

Absolutely, lapstrake or clinker is wonderfully traditional but a lot of people perhaps question their own ability to complete the boat. I would imagine the difference in weight between same length boats built in lap compared to a Storer design would be significant.

Wonder what boats have been consistently good performers in RAIDs. Not the big skiff type boats ... but the Oughtreds and other sensible boats that get speed from refinement.

Mik, I wonder how much the crew skill and determination rather than design has influenced the more casual Raid results.

Originally Posted by m2c1Iw

Mik some delving questions, here are my thoughts


Singlehanded not a critical element, assumed trailer launched and hard to move ashore.

Yes but with flatish aft sections an off wind flyer with some extra length for improved upwind speed.

flatter sections don't work as the skiffs have found. The boat is doggy upwind and hard to control downwind. Rocker is the critical element and another thing that is a bit of a trade secret (not really .. but I don't want to make it more obvious to other designers than necessary - anyone can work it out from observation and other things I have said in other places - I'll tell you next time I see you!)

From my reading the Raid handicapping and class specs are somewhat loose the organisers appear to divide entrants based on length and performance from previous years. The main object being to participate and have fun and entrants should avoid being overly competitive.

Yap ... but massaging is always nice if it can be in the context of keeping the boat nice to sail

My interpretation of a competitive boat is something with good hull speed over a wide variety of conditions so as not to be left behind by the bulk of the fleet not necessarily the fastest boat.

Exactly .. that is what the double enders do so nicely. Quite low wetted surface meaning high average speeds despite the speed limitations of that style of canoe stern.

Absolutely, lapstrake or clinker is wonderfully traditional but a lot of people perhaps question their own ability to complete the boat. I would imagine the difference in weight between same length boats built in lap compared to a Storer design would be significant.

Not so much in the methods, but there is a lot of excess structure there that makes not contribution to the sailing performance. Always good to ask ... "what is really needed" and "what is the lightest reliable structure I have seen work".

Mik, I wonder how much the crew skill and determination rather than design has influenced the more casual Raid results.

I've alluded to that in my last comments in the Caledonia RAID thread. Joost and crew (name please Joost!!!) did very well to keep things very consistent.

Here is something I wrote to Chris Perkins last night ... him first

Congrats on the GIS success. I would have liked to have seen the Caledonia - there are plenty of good vantage points along the route for good snapping - but the thing clashes with the HBBR Norfolk Broads meet, and the Norfolk Beer is too tempting.

I was chatting with another participant at Beale who had observed how well Joost was doing - his comment was that he didn't think there was anything to touch her downwind but she wasn't quite so electrifying upwind. My guess that the notorious Loch Ness chop would have had something to do with it, she must have been slamming quite a bit. Very short steep waves that break all too readily. I reckon Joost did very well indeed.
Head back home next weekend

And from me

Doesn't sound like the Goat was toooo bad upwind - otherwise there would be some bad results in the very consistent set that Joost put together. Wonder how hard they were sailing it?

Also sailing flat bottomed boats takes a bit of getting used to - the bias is to let them heel, but it is better not too. Cram a bit further forward and sail flat with lots of leaning out. A bit of practice trying different methods might indeed make a big overall difference - there might be better ways than I describe. If their sail was very flat that might make some difference too. Need a bit of depth, particularly in the bottom of the sail to punch upwind - so the laced foot might be replaced with an adjustable loose one and a RAID41 style boom.

Anyone for a carbon mast? - getting that weight out of the bow would make a difference too - but too rich for my tastes.

The GIS bow is very fine indeed and lots of modern raceboats are not dissimilar. You ever seen the very sensational UK Cherub site. These are the more uptodate designs - showing some VERY similar to the Goat http://www.sailingsource.com/cherub/desp90.htm. They do have a trapeze to get power upwind though ... so again might be power that helps the flat bottom go really fast.





Additional comment - the faster and the smaller it is the more affected by chop .. so to have something as quick and short as a Cherub (12ft) with similar flat bottom profiles to the goat is quite interesting. The flat bottomed ones should just not be competitive at all if there were significant problems. These box shapes are derived by the same designer of the similar skiff moth shapes

Anyway, my chain of rationalisations ... say it is not the boat (yet)! Maybe it is more a list of the things I would try before saying it is the damn boat!

MIK