Hobie 18 Spinnaker Group Buy Feeler, Any Interest?

The spinnaker set up can be pretty simple. I took a windsurfer mast and cut to length 12'. I then cut a split on the bottom so that the end of the pole would go over the rod going down to dolphin striker. I then had a simple bolt go through the pole on the back side of striker rod to keep pole from slide forward and back off striker rod. I used 2 wires as a bridle at the end anchored to the same fittings as the bridle for the for stay. I used bungee to hold the pole up to the bridle. All of the force on the pole is going to be pulling it up and to the side the chute is on. Most of the force is simply up. The wires (or line) is what supports the force. How hard you pull on the halyard will determine how strong those wires need to be. I used a lever type jam cleat on the mast for the halyard. Simple turning block up on the mast.
Some folks use a bailer with the block a bit above the bailer. I just used the turning block. The tack line to the end of the pole I just used a jam cleat on the front cross bar.
These spinnakers are not very big and pretty simple to operate. Just remember, not to try and take it too high. That is where you will load up everything where you might be in danger of breaking the pole or something and then just steer down and pressure will come down. I used the amount of bend on the pole as guide on how high I would sail.

If you want more strength in the pole you can add a stay in the middle, basically a rod aiming down. You then tie a support line from end of pole to bottom of pole. Make it very tight where it bends pole down. I do not think it is necessary unless you are mixing it up real heavy in races. This would be where you push the boat up very at a very high angle for strategy purposes against another boat. For me, I do not think it will be that necessary.

Of course, if money is not a big concern then go all F18 with snuffer etc. It will be fun either way.

Cheers

Ok guys, I updated the first post with a list I started on the required hardware and line to set this up. Read and post any changes, additions, suggestions etc. I'm not familiar with the halyard rigging for a snuffer setup so I'll leave that so someone else unless I find a nice diagram to post.

Some line diameter suggestions for the sheet, halyard, and control lines would be helpful at this point.

Sounds like I am the only one hoping to furl like a Code Zero? Anyone know if this whirlwind sail would be flat enough to be suitable for that? Are there other considerations (luff reinforcement?) I'm not thinking about?

Already have a carbon sailboard mast to use for a pole; I bought one off CL to make a righting pole out of and they're so cool I picked up the other one the guy was selling, 'just in case.'

Now if only I could get the boat near the water...

I don't know for sure but I believe anything but a true Code 0 requires a top down furler due to the amount of material. You could add one but they are a little more expensive. Bag/snuffer just seems to be the standard for a downwind sail. It's a relatively flat cut like an F18 but still probably has too much of a buldge to use a normal furler on. You also dont take the upwind drag penalty of having it furled up in the air the whole time it's not in use.

If you're looking for a spinnaker sail, then it's best for the snuffer system, if you want a code zero sail (a specific type of sail that is just barely out of jib range for racing) that's cool, but they are two different sails. I did a bunch of playing with a newer cut F18 Tiger spinnaker last year and found the mid pole snuffer to be pretty nice. One of the nice things about the snuffer setup, is that if you want to play spinnaker sailor before a class race, you can, and then just drop the pole and halyard and you're back to stock class legal setup.

I have the old style (Hogs Breath 1000) H18 spinnaker and happy to help with advice if wanted. It's a huge balloon cut compared to the current flat cut used today but still useful.
My only suggestion from the photos already posted is that the H18 spinnaker attachment points were the rear beam (not front beam) and stays. Love to see these documented once setup and bought.

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2007 Hobie 16 - 'Slingshot'
1996 Hobie 18 - 'Onrails'
Hobie Bravo - 'Hobie Bites'

That's not entirely accurate. There's a fair amount of compression along the pole. You want to be able to put a curve into the pole by pre-tensioning everything with a line that is where you have a bungee. That keeps the forward end of the pole relatively stable so it maintains halyard tension. The worst thing that can happen is for the pole to invert (bend upward) - you loose halyard tension, the spin balloons and loads up. If you don't blow the sheet quickly, you're likely to break the pole.

Seems like since the bridles going to the end of the pole apply a decent amount of compressive force on their own, couldn't you get the pole to prebend just by shortening those and not need a line pulling up on the middle of the pole at the forestay bridles?

So you've made that old spin last this long huh? Impressive! From what I've read the older style spins used a really long foot that required the sheet blocks to be on the rear beam. The Whirlwind spinnakers foot is around the same length as a Hobie Tiger's spin foot according to Chip so the recommended sheet location is more midship towards the front of the boat.

On a side not I was looking at my boat today and realized if we put cleats on the shrouds or on the deck near the shrouds the sheet will have to wrap around the dagger board unless you just leave them all the way down when sailing off the wind, which is more rare. I'm thinking now that maybe attaching it right behind the jib track might be a viable location since you could get some good material to screw into with the tramp track and hull lip without any risk of putting a hole in the sealed part of the boat.

My Ratch-a-matics are attached to the 7-hole shroud plates, and yes, we leave the daggers down all the time to avoid 'blockage' of the spin sheets.
I find this gives us more precise steering, which is needed at speed.
I can recall (before mounting the spin) running downwind with the boards up, and the H18 would 'wander' a bit from side to side.

The first season, we had quite the learning curve, experimenting how to go 'across' the wind more to 'heat it up', and then carve more downwind to 'cool it down'.
So we now sail at about 135 degrees downwind in a series of carved turns, always searching for that optimum point,
The faster you go, the more the apparent wind moves forward.
Thank goodness for Higher Performance Sailing II, what a book!

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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.'

So your blocks and cleat are mounted to a 7 hole? Seems like there's not much space left on a 7 hole for both. I have 10 hole plates but that's just for ease of mast stepping. If you only use the cleats in light air then I guess it really doesn't matter where they are.

So once you turn back downwind with the added apparent wind why wouldn't you just be able to continue at that speed, assuming no wind shift, instead of having to go back to a broad reach to heat it back up?

Because when you shift downwind you bring the boat out of "equilibrium" at that faster speed, meaning that the driving force (at that angle to the wind) is no longer as strong as the resistance, even with the added boat speed. You wind up bleeding off speed and have to come back up to gain it back. If you think about it, it's essentially the same reason that, on a windy day, you still can't get a jetski to give you an extra 5mph tow and then maintain the extra speed, despite having the added boat speed/apparent wind. Just a little less intuitive.

Also, wow! You've added a ton of documentation to that first post! Great information, really spells out the rigging and hardware setup for a spinnaker!



Matt, your explanation about pole pre-bend makes a lot of sense. I knew I'd heard that inverting the pole bend was bad, I just didn't really know why. Should've drawn a free body diagram!

I understand that you would be going slower than the speed you were carrying on a reach it just seemed like whatever speed you were now capable of with the increased apparent wind you would be able to maintain at whatever angle was 90 degrees apparent.

And yea, I'm slowly adding anything useful I find to get everything under one roof. I had to do a quick photoshop on that H16 spin diagram to make the tramp look more like a H18. Was driving me nuts lol

Also, what diameter shin sheet is the norm? I see on the Tigers line guide they run 5/16". I assume its a compromise between something large enough to comfortably hand hold vs the weight of all the line having to go around the forestay.

We use 10 mm Robbline, light, thick enough for a good grip, not cheap.
There are many equivalents in a high tech line.

_________________
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.'

What type of Halyard do you use? In one video the guy mentions not using line with any polyester in it to reduce the change or line burn on the sail when dousing.