GIS handling characteristics

**callsign222** · 18th June 2010, 11:17 AM

Since we've got 4 people that are starting to sail their GIS for the first time, I thought I'd start this thread.

I have extensive racing experience in Blue Jays, Lasers, 420's, FJ's, and recreational experience in Beverly dinghies and Beetle Cats. All marconi rigs except for the gaff Beetle Cat. I am an athletic 30yr old and weigh 150lbs.

The first time I went sailing in my GIS it was in a force 2- light breeze with my wife. The boat handled superbly.

I went sailing today for the second time in my boat, and I was by myself, and it was force 3- gentle breeze with some higher gusts. I got spanked by my GIS in ways I didn't even see coming, and I'm surprised and a little humbled. I went sailing planning on a picnic as I cruised up and down the lake tweaking the rig. Instead, I went swimming.

So, as I headed out things were looking good. It's 65F (18C) and overcast, with a good breeze and slightly chopped water. I was un-reefed full sail, sitting on the rail and humming along, with a little bit of heal. A gust came up that I saw coming and I let out the sail a bit. This did not stop the boat from going over. I completely let go of the main and dumped it, but she still went over. Water poured over the gunwale, and that was it, I was in the drink and my flip-flops were floating away. That was fast. I swam around and clambered up on the daggerboard, no problems there, she came right up but obviously swamped. Balancing the boat was precarious. The nose was down, and I feared a breach in the forward compartment. I bailed her out with my 5 gallon bucket, and checked the forward compartment, it was dry.

I decided to reef. My sails are the stock Duckworks sails, with no reef points except the grommets along the luff and leach, its the full-batten idea.

In my personal opinion, the full batten idea is not conducive to reefing underway, especially with a sail this large. I was skeptical when I ordered it but decided to go with it anyways since it came with Mik's recommendation and he looks so comfortable on his beautiful Beth. I found that that when situated in the bow of the boat the GIS is highly unstable due to its narrow beam in this area, and this was in only lightly chopped water. I tied off the "new" tack of the sail and then tied off the clew and re-hoisted the sail.

The full-batten sail with two reefing points cannot exert enough pressure along the boom to keep the sail folded up. Despite repeated attempts at re-tensioning the clew and tack and "new" outhauls I was not able to get enough tension along the "new" foot of the sail to keep it under the batten. As the chop increased, it became a more precarious situation to sit up in the bow fiddling with the tack. I attempted to keep the boat pointing in the wind, but with the large windage in the bow, it kept falling off the wind. A mizzen in this case would have helped immensely. Kudos to Clint and John.

Sailing a half-way reefed sail with a large pregnant foot billowing out I sailed close to shore and dropped anchor.

Dropping the rig I sat up in the bow to re-tension the new tack and clew, and found myself back in the water, as I capsized again, quite unexpectedly. As said before, the boat is unstable with no one else on board and the sole occupant up on the forward seat. This happened really quick.

I bailed the boat back out and made the tension along the reefed foot as tight as possible. As I headed back out to sail some more, the boat really moved along with the first reef. Exhilarating! However, the sail pulled back out of the batten, and I got the "pregnant" foot again. This is not conducive to pointing into the wind. At one point, I could not even tack, the boat kept falling off. I was almost forced onto some rocks, so I jibed around to remedy the situation. This was immensely frustrating, as you can imagine. Was it due to the rather flat head on the Duckworks sail?

Needless to say, I found that the GIS exhibits the following attributes:

*Difficult to de-power the sail in gusts. (is this an attribute of the balanced lug? I have zero experience with this)

*Unsteady when sole occupant is in the bow.

*The full-batten two-grommet reefing idea is either frustratingly difficult to accomplish successfully or only viable when launching reefed-- reefing underway with this fashion system is precarious at best.

*Boat has difficulty tacking through the wind when reefed.

Obviously I would like these remedied. My multi-day Maine coast trip is at risk unless I can figure these out. I'm happy I didn't finish in March, or it would have been a very cold day indeed. My sail is going to get extra reef grommets immediately prior to any more sailing.

These are my first impressions of the GIS, but I would like to hear yours, or from anyone who can shed some light on this issue. The lug rig, as I understand, is a "reef early, reef often" rig, and I can attest to that. I would also like to know why I wasn't able to depower the sail to stop the capsize.

Oh, she looks really pretty at anchor as viewed from the shore, and I continue to get "thumbs up

" when driving on the highway.

(Michael Storer writes - I have some specific checks for the goat rig if these types of problems are occuring ... skip forward if you want to see quickly some points ot check to make sure the rig is set up properly or read through to get some extra info from experienced users - either way you will end up in the same place
https://www.woodworkforums.com/f169/g...ml#post1168588)

**keyhavenpotter** · 18th June 2010, 10:07 PM

Sorry that you had a hard time, however your post will lead to learning from it. It is important for others as well as yourself. I have not sailed a Goat but have used the lug rig and have been beaten up by a lightweight flat bottomed dinghy, the RAID41.

The rig issue and reefing the sail are all solvable. It's a big rig, 50% larger than a Laser or the Scow sail I use. Reefing ties, a good efficient down haul should solve the sail issues. There is no intrinsic reason for sail issues - I have raced the lug rig up to 30 knots in flat water. I feel strongly that 6:1 should be used for the downhaul. As the wind increases I use more and more downhaul to flatten the sail. This is impossible in weak non-roller bearing setup.

The hull issues? Let me say this. I found the flat bottomed hull shape had a huge difference in stability between lightly loaded and with more heavily load.

For example, if I sat down on the side decks of RAID41 the hull would slip sideways away from me and capsize, like a bar of wet soap. No chine grip at all. However when the ballast tanks ( about 80kg) were full, she was completely different.

Not only could I sit comfortably on the side decks but another chap joined me and she almost held both of us. The sideways slipping away had disappeared completely. She felt very stable.

Is it the case that these ultra light flat bottomed boats handle fine with weight immersing the hull somewhat, but with little load there is much less hull grip on the water.

Going forward to reef with no load in the back of such a light hull might immerse the narrow bows and lift the back half, allowing capsize too easily.

The question is, when sailing alone should some weight always be carried so only the good handling characteristics are shown?

Brian

**m2c1Iw** · 18th June 2010, 10:37 PM

Brian may wish to comment on your downhaul set up but to my inexperienced eye the way you have the line running out to the tack looks to me as it may tend to hold the boom amidships or at least put odd tension on the sail and yard. Just a thought.
In this pic the foot is loose but then there is little breeze.

**PAR** · 18th June 2010, 10:54 PM

With your reefing arrangements and level of sailing experience, you knew you where going to be fairly helpless if you had to tuck one in. Once you realized you couldn't continue under the full sail plan, you again knew what the best choice was.

I suspect once you've made better reefing arrangements, you should have no problem handling the boat.

**callsign222** · 18th June 2010, 11:42 PM

All in all it was a good time, and I'm happy with the boat, she just fed me some humble pie, and I didn't see it coming. Humbled I am-- which is good that it happened this early on a lake and not off the coast of Maine in a thunderstorm.

Great comments. I already have the hardware to make the downhaul more aggressive. Hopefully more purchase on the downhaul can eliminate that odd line from the tack. Without it, I'm not able to get the lug to balance right, it kept swinging way forward, but I've only rigged the boat 3 times now.

In that picture, it's my first sail, and the sail is not appropriately tensioned at the tack. However, would it behoove me to run a line along the foot of the sail instead of the individual ties to snug the foot up to the boom?

Ordering up some grommets and sail material today. Maybe I'll look into some ballast to augment my 150lbs.

Keep 'em coming guys.

**woodeneye** · 18th June 2010, 11:54 PM

Hi Christophe,

Thanks for making this post. It mustn't have been an easy thing to do, but it's important from the point of view that others like me can learn from your experience. Under the circumstances, I think you did very well, and I dare say you are a lot wiser for it!

Clearly, your sail could not be reefed properly without reef points between tack and clew. This can be fixed, so that you don't experience the problems resulting from that "pregnant foot" again. By the way, that is a very apt description!

Your downhaul doesn't look powerful enough to flatten the sail sufficiently to depower it. As Brian has said, he uses a 6:1. Now that's a LOT of power, and gives you an idea of what is needed for it to do the job. Cranking up the downhaul creates a much flatter sail up top by bending the yard, so that would have helped considerably. It does sound to me like you had a lot of power to deal with. Remember, 105 square feet is a lot of sail. My brother who sails a Paper Tiger has said that I'd better reef early or my undies won't cope with it!

I can understand your concerns but please remember this was your first sail by yourself in a new boat that you are still learning. In one sail, you have learned an awful lot, and so have we.

The other thing to remember is that the GIS is designed for a crew of two. I think that with your wife aboard that day that you would be telling us about an entirely different experience.

I have a question for you. How much daggerboard did you have down? The Goat has quite a substantial board and it would provide enormous grip if it were all the way down in such conditions with just your weight. Perhaps maybe too much grip was a contributor?

The other encouraging thing for me is this video of Mick. Definitely more than Force 3 here and yet he's in complete control. Note that when hit by the gusts, and he spilled the sail, the boat recovered instantly. Note also that the foot is very taut and it appears that he has quite a bit of downhaul employed. Also, the board is not all the way down so that after he gybes or tacks and tacks and the boat has very little forward momentum, it can slip sideways slightly as she powers up again. If it couldn't do that he would be swimming too.
[ame=http://www.youtube.com/watch?v=Xy4_OTodVTg]YouTube - Shooting the Breeze[/ame]

**keyhavenpotter** · 19th June 2010, 12:37 AM

Originally Posted by callsign222

Without it, I'm not able to get the lug to balance right, it kept swinging way forward

Hi, that's a clear indication that you are way to short of downhaul. The downhaul sets up the whole rig and you should be pulling hard to very hard to set it up. We regularly break things with the amount of downhaul we use, the whole set up has had to be developed to handle the tensions.

The thing that most needs thinking through for me, is that if a singlehander goes forward in waves to reef, the boat should not be capsizing on him. Again, perhaps ballast is essential for singlehanding?

Brian

**callsign222** · 19th June 2010, 01:23 AM

Bruce, I actually posted this last night on my blog:

Laser: 76 square feet of sail (crew of 1)
Beverly: 66 square feet of sail (crew of 1)
Walkabout: 80 square feet of sail
Mayfly16 91 square feet of sail
Beetle Cat: 100 square feet of sail (and 450lbs hull weight!)
FJ: 100 square feet of sail (crew of 2)
420: 140 square feet of sail (crew of 2)

You're right, if my wife was on board, it would've been a screamer of a day, no doubt! Good times. I definitely was missing her weight on the rail.

Brian,

Thanks for the note on the downhaul, glad it's a clear diagnosis now. I'll go out and fiddle with a new set-up right now.

Just to clarify, I'm not worried about the boat being fundamentally flawed (it's not), I'm tapping into the collective intelligence here to help me master her quicker, rather than re-invent the wheel. And this is all part of the fun of sailing a new boat and a new rig! It wouldn't be anywhere near as fun or satisfying if I went out and was bored all day!

**robhosailor** · 19th June 2010, 04:26 AM

Hi All,

I'm using a simple* proportion to compare different small boats:

X = L x B/S

L - lenght of hull [metres]
B - beam of hull [metres]
S - sail surface area [sq metres]

So:

"X" of Laser International Class is circa 0,82 (similar to cruising dinghy!!!) ... ???
"X" of GIS is circa 0,74 (similar to many cruising dinghies and daysailers)
"X" of Finn International Olimpic Class is circa 0,62 (racing dinghy)
"X" of 505 International Class is circa 0,68 without spinnaker (racing dinghy) and circa 0,24 with spinnaker (very high performance racing dinghy!!!)
"X" of 470 International Olimpic Class is circa 0,63 without spinnaker (racing dinghy) and circa 0,31 with spinnaker (very high performance racing dinghy!!!)
...
"X" of Beth sailing canoe is circa 0,52 (high performance racing dinghy!)

I don't remember L, B and S for Raid 41 ...

___
*) it's too simple for really accurate comparisons (see "X" for Laser!!!), but usable for many quick and simple applications like our forum - I think.

**Joost** · 19th June 2010, 05:55 AM

Hello,

The GIS is a very big boat to handle by one person from F4 onwards when under full sail. There are two options when the wind is stronger:
1. more ballast (your girlfriend!)
2. smaller sail area (timely reefing)

I have the standard Duckworks sail as well, but with a set of reef grommets for the first reef. I sailed the first few months with the battens in, but now they are in my garage stored away (more power without the battens it seems). One thing I think that might be worth considering when either sailing solo a lot,when participating in raid like events or camp cruising would be to have another set of reef points in between the the current first reef and the full sail. Below picture shows the standard Duckworks sail I have, and you can clearly see that the first reef takes away a fair amount of sail area. With the suggested added set of reef points, it allows for the following: 9.7 m2 (full sail), 8 m2, 6.5 m2 (current first reef) and handkerchief size (current second reef).

With regard to your questions/comments:
*Difficult to de-power the sail in gusts. (is this an attribute of the balanced lug? I have zero experience with this) - The sail is quite powerfull. I agree with the comments above regarding using a more effecient downhaul system. This is how I rig mine:

*Unsteady when sole occupant is in the bow. - The boat is very narrow in the front which has its advantages but one big advantage is that it is unsteady when you are by yourself and you have to go forward. There are some threads on this forum on ways to lead the halyard and the downhaul back to the midseat.

*The full-batten two-grommet reefing idea is either frustratingly difficult to accomplish successfully or only viable when launching reefed-- reefing underway with this fashion system is precarious at best. - I agree, that's why I chose to have some reef grommets for my first reef.

*Boat has difficulty tacking through the wind when reefed. - What I find with the GIS, not only reefed but also under full sail, is that it helps to steer the boat in gentle curve through the tack rather than make it a short turn (in that case she tends to come to a full stop in the midst of a tack).

*I would also like to know why I wasn't able to depower the sail to stop the capsize. - In this situation I usually point the boat a bit higher meanwhile letting the sail out by whatever is needed. I have never come close to a capsize (yet).

The GIS was designed by MIK for a crew of two. Most builders however are using the boat for sailing solo. This means that the builder needs to think a bit on the sail area he/she can manage (timely reefing) and running rigging. But she will allways be a big boat for one (to put in the water, to row, etc.), hence the Son of a Goat project:
- GIS, for a crew of two with the option to sail solo
- Son of a Goat, for a crew of one with the option to sail two-up.

Hope this helps.

Best wishes and good luck,

Joost

**robhosailor** · 19th June 2010, 06:02 AM

Originally Posted by Joost

The GIS is a very big boat to handle by one person from F4 onwards when under full sail. There are two options when the wind is stronger:
1. more ballast (your girlfriend!)
2. smaller sail area (timely reefing)

Most of small unballasted sailing dinghies (and small cruising cabin boats too) needs to be reefed form Force 4...

**PAR** · 19th June 2010, 06:05 AM

A much better way to make these "comparisons" Robert, is to use the percentage of sail area to wetted surface.

**Joost** · 19th June 2010, 06:07 AM

Hello Robert,

Yes, I agree. The issue is however that a lot of people compare the GIS to a performance dinghy, for example a Laser. This latter boat never reefs (it is not capable of course, but most experienced Laser sailors are quite happy sailing the boat in stronger winds than F4).

What I tried to point out is that the full sail of a GIS becomes quite large for most people in anything above F3 (so already in the lower scales of a F4).

Best regards,

Joost

**robhosailor** · 19th June 2010, 06:10 AM

Originally Posted by PAR

A much better way to make these "comparisons" Robert, is to use the percentage of sail area to wetted surface.

Yes, I agree, but data of wetted surface are not available often. L, B and S you can see very often.

...
Joost - I agree

**callsign222** · 19th June 2010, 06:49 AM

Originally Posted by Joost

The issue is however that a lot of people compare the GIS to a performance dinghy, for example a Laser. This latter boat never reefs (it is not capable of course, but most experienced Laser sailors are quite happy sailing the boat in stronger winds than F4).

I think this was part of my problem. I saw the wind, the wave action, sniffed the air and headed out with a full head of sail.

Joost, fantastic reply, thank you.

I've already got the sail at the sailmaker for grommets along the current reef points. The sailmaker also suggested another line between the foot and the first reef, but I said no, citing that Mik had the sail set up the way it would work best. What do you think, is a call in order to change the work and add another line?

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