Hobie 18 Spinnaker Group Buy Feeler, Any Interest?

can someone please remind me again why its not just easier/cleaner to get a flatter spin/hooter/code zero and furl it?

with all this back and forth regarding the pole/pole length/pole weight/pole cost/pole strength/snuffer/SNU, etc....sounds like more margin for error/failure/pain in the ass.

the Hobie Pearl furls whatever you want to call its spin. looks pretty rad to me. is the only issue the drag it causes? does that truly cause more drag than the ugly big mouth bass snuffer contraption?

Most of the small to mid size tri's have furling spins - is it really slowing them down that much? if its so much drag why don't they simply install a snuffer on the middle hull and not furl?

I always thought the big mouth bass snuffer contraption looked cool. If rigged properly it seems like it's almost as convenient as furling since it's just one line to pull up or down. Cost wise I can fiberglass a snuffer ring and sew a bag on myself for next to nothing. But I can't fab a furler very easily, and I believe the extra cut of the spinnaker, even a flatter more modern design would still bunch up in the middle when you tried to furl it. A top down furler would be needed for extra $$

Also it seems the consensus after looking around that a H18 doesn't generate enough speed to get enough apparent wind to make up for the extra distance traveled with a reacher vs spin

But besides all that if I'm ever on a long distance trip I have a 3rd toilet available for when the hull hatches fill up..

I do realize the pole is required for a furling system as well.

Was just curious as to why the snuffer is better than a furler. Is a spin better than a reacher/code zero? ive done some reading and as far as i can tell they are simply two different sails. there is not much info on which is faster/better or why you would choose one over the other. what is on the Hobie Pearl? reacher or spin? it does not bunch up or look bulky when furled so im assuming its not considered a spin. is it smaller than the spins used on F18 boats, or what you guys are talking about installing on your H18s on this thread? is it slower? is furling difficult during strong winds in the middle of a buoy race?

I mean when I get mine in a month I'd be happy to ghetto rig a spare H18 furler I have sitting around to the pole tip and see what happens if I try and furl the spin lol.

Everything else is just speculation and hard to compare since it would be hard to find someone to do a direct comparison between sails. In the mean time I wouldn't know what to tell you about what code number this whirlwind sail is other than its based off a Hobie tiger spinnaker if I'm remembering my conversation with Chip correctly. He modified it a few times to this version we have now. it makes sense that it would be slightly smaller than a tiger spin overal since he had to shorten the luff to 25.5' for the shorter mast and kept the foot the same as a Tigers.

I'm sorta new to all the details on how different designs work with different boats but the meat of it is that the faster a boat is naturally the less power it will need out of the sail and the more apparent wind it will create sailing downwind. So it can get by with a flatter sail and maintain the higher speed and jibe downwind and overall be faster to the mark. The opposite is true in the case of many monohulls which must have big curved symmetrical and asymmetrical sails and more or less sail very deep down wind.

The question is on a cat is how flat of a sail can you get away with and still get enough apparent wind to maintain speed downwind without having to take a much farther path to the mark by going back on a broad reach to keep the sail powered up. The way I figure it if faster hulls than mine are using this cut of sail the last thing I'm going to do is have it cut even flatter if I'm trying to go downwind faster.

This is what I suspect –

The spin is light and fuller/bubbled than a reacher/hooter. It is for going deeper and faster downwind. Too much material to furl

The reacher/hooter is thicker material and flatter than the spin. Its not great downwind, but fast on a reach, the closer to 90 degrees to the wind the better? It can be furled but it must be flat and not flogging to furl neatly.

Spin is for downwind, reacher for reaching? Spin needs the bag/snuffer….reacher can furl.

Like I said, there's people on here that could write books on all this stuff, but from what I've read while trying to understand all this myself you are more are less correct. Technically if if your boat is fast as balls you could go as deep as you want with a reacher. You could still travel downwind in a cat with one, but you would be sailing higher to power the sail and probably have a slower VMG to wherever you are going than a bigger spin with more power that you can run a little deeper with. Some of the big daddy boats are carrying like 5 or more head sails depending on the direction you are wanting to go. Cats can get by with less sails because of the extra apparent wind allows a sail to be used in a wider range of the wind circle, but still each cut of sail would be ideal in different circumstances. In other words just get one and go play. I confuse myself just thinking of all the variables.

So I wouldn't try and think of it as one sail being better than another, there's a lot of factors depending on what you are using it for and on what boat.

The idea is that a wing/sail/foil with more camber or more shape generates more lift (hence more "power") at a given speed, at the expense of more drag. A thinner/flatter wing/sail/foil with less camber/shape generates less lift at the same speed, but also less drag. This is, in layman's terms, the concept behind "flaps" on an airplane. At takeoff and landing, the plane is travelling slower and needs to provide more lift at slower speeds, so it uses flaps to change the effective shape & camber of the wing, generating more lift, but at the expense of more drag. In order to go faster at altitude, the flaps are retracted. If you compare the cross-section of the wing on a fighter jet to the wing on a boeing, to the wing on a prop driven plane, you'll notice the same differences.

Because catamarans have less resistance in the water, they need to/can afford to generate less lift at any given apparent wind speed than a monohull, and therefore benefit from a reduction in drag. A fuller sail would generate a lot of lift, a lot of drag, and result in a slow boat that heels over constantly. In terms of spinnakers, you're looking at the same principles. A monohull uses a very full spinnaker as basically just a big parachute to pull the boat downwind - all drag, no lift. Catamarans use a reacher/spinnaker/code 0 to generate lift and drag both, using the apparent wind to maintain airflow over both sides of the sail. As far as which has more benefit on what angles - fuller or flatter, beam reach or broad reach, you'd have to talk to someone with experience experimenting with different sail shapes, probably a sailmaker. With all the science behind it, sailmaking is still somewhat of an artform.

_________________
Mike

'79 H18 standard 'Rocketman II' sail #14921 RIP
'78 H18 (unnamed) sail #14921
'08 H16 sail #114312
'97 H21SC sail #238

I'll add some clarification to the comment about monohull spinnakers, specifically asymmetrical spins.
Just like on a cat, the asym on a monohull does generate lift. depending on the boat: (a planing Melges 22 vs. a displacement J109) varying lift is generated dependent on wind speed, downwind angle, angle of attack. I worked the pointy end of a racing monohull for 10 years and we always work between VMG and DTM on a constant basis during a downwind leg.

now for a 'square set' spin, set on a mast anchored pole, the amount of lift generated is little, unless the angle of attack is extremely shallow, which defeats the purpose of the square set.

then there is the 'lift' effect the spin has on the hull, bringing it up out of the water, but that's a different story.

_________________
Chris
'88 H18SE Arís

Moderator, please chime in here...

has any other topic filled up 4 pages of Forum so quickly?

Love it...keep the posts going, lots of good words from good folk.

_________________
2015 H16, with spin,
SOLD 1989 Hobie SX18 Sail # 1947 "In Theory..."
'Only two things are infinite, the universe, and human stupidity. But I'm not sure about the former.'

Good explanations guys. I've read a few posts about other cats where people said their spin made the bows dive and needed a rigging adjustment. What adjustment would fix the bows diving if that was the case?

Personally, I've just heard that spins tend to lift the bows, not sure about diving. Maybe John Lunn can answer that question. I have however had my bows dive on me without a spinnaker... I was hit by a pretty strong gust on a broad reach, and even with my crew and I sitting on the rear crossbar, the bows dove and the boat pitchpole'd immediately. Was probably pretty spectacular looking from afar. A lot of driving force up high, particularly on your mainsail will cause your bows to dive, but I would think that the lift on your spin is a bit lower and less likely to do that to you. I used to rig my mast very far forward, not knowing what the "right" position was, which was probably a factor in my pitchpole.

However, thinking about the effects of a spinnaker, it would seem that a spin would shift the center of effort of your sailplan much further forward, resulting in a pretty good amount of lee helm (where the boat is naturally trying to turn downwind rather than upwind). So, folks that already have a spinnaker, do you find that you have to push on the tiller to maintain a straight course, or does it not make much of a noticeable difference?

The spinnaker will provide quite a bit of lift on the front of the boat. It basically provide more balance to the boat than without the spinnaker in down wind conditions especially as the wind picks up. A cat without a spinnaker in big breeze will have a lot of force pushing on the bows when going down wind. You typically respond by reaching up a little and then struggle with getting just blow over sideways. It the wind continues to build there will come a point when the main has so much force that the bows no longer have enough floatation to keep the boat from pitch poling. The spinnaker will help this some by helping keep the wind force more evenly distributed and reducing some of the force on the main to push the bows down. (It feels like the bow is lifting) when it might be more accurate to think of it as using more of the pressure forward in the spinnaker. You will constantly be trading off how low you can go versus how high. If you go up your turn over side ways, if you go down you bury the bows. That we used to refer to as the line of death, when those to lines become so narrow that they come together, you just end up ...dead.

The solution in those big wind conditions would be to have smaller sails. For big wind a smaller main and a small spinnaker would likely result in a faster boat in those conditions. But that is for a different thread.

So lets say you go over with the spin out. Would you want to try to suck it into the snuffer before righting or is that asking to tear since it's probably all bunched up over everything?

Most activity on a Hobie 18 topic in... decades? maybe?

_________________
Matt Miller
Former - Director of Parts and Accessory Sales
Warranty and Technical Support
Hobie Cat USA
(Retired 11/7/2022)

This thread inspired me to hoist the yellow sail yesterday, loads of fun.

Photo posted to FB, will have to work out how to post it here too

_________________
H18 Newbie, Too heavy for the 14