New Owner of Hobie 18

Hello, new Hobie 18 owner here. I sold my 25' sport boat and just picked up this 1981 Hobie 18. Been watching and reading everything I can but have a couple questions so far.

You can bring the jib in toward the mast all you want. Are there some basic guidelines for where you set it for wind speeds?

And what does the wishbone yoke coming off the mast and attached to the boom adjust? For de-powering? Thanks

I think I posted this under the wrong topic the first time.

Hello, new Hobie 18 owner here. I sold my 25' sport boat and just picked up this 1981 Hobie 18. Been watching and reading everything I can but have a couple questions so far.

You can bring the jib in toward the mast all you want. Are there some basic guidelines for where you set it for different wind speeds?

And what does the wishbone yoke coming off the mast and attached to the boom adjust for? De-powering? Thanks

First, welcome to the club. You selected a great all round boat. There are some good books out there that will give you plenty of information as you learn about the different adjustments to the boat. "catamaran Sailing from Start to Finish" by Phil Berman is a very good one, simple to understand.

As to your questions, Generally speaking the jib is trimmed to the point of sail (direction the boat is relative to the wind). For different wind speed it is about "opening the slot" the distance between the main sail and jib. The jib's purpose is to help accelerate the wind on the back side of the main, giving the boat more power. As wind builds, you would want to open this "slot".

Regarding the wishbone on the mast, this is for adjusting the mast rotation. It is tied to the boom and by adjusting the line in and out affects the amount of mast rotation you allow. Best thing to do to see what effect this all has, is to set up the sails on land, preferably in little wind. Pull you main sheet in all the way with the traveler all the way to center. Look at the main sail as you rotate the mast and pull the down haul of the sail. Let it out and pull these in. What the effects it has on your sail shape. Make small adjustment to the main sheet while doing this. You will then have an idea of how much you can change the shape of your primary wing (main sail).

As you learn, these changes will make more sense to you and will have more control of the boat in different wind conditions.

Good Luck

Welcome! I had a 1981 Magnum 18 and now have a 1998 SX. The boat is great and you will have a lot of fun with it. To answer your questions:
1) jib is trimmed like any other sailboat.
Upwind course: ease until you see a luff, trim just enough to stop the luff. Then trim main the same way and you will have a pair of sails creating a slot effect and good lift.
Downwind course: ease to put sails perpendicular to the wind. You are looking for maximum push since you won't get lift.
2) that hardware is referred to in the manual as the MRCY and Hobie never defines it, but it stands for Mast Rotation Control Yoke and it's used as described above.

Speaking of the manual, do a quick search on these forums and download the Hobie 18 Assembly Manual and the Parts Guide. They are both invaluable and after a bit of rigging and mileage on the boat, you will have them memorized.

Also consult these forums for good posts on
Redline hulls
Soft spots on deck
Rudder pins
Sails & rigging advice
Trailers & cradles & beach wheels

Enjoy!

_________________
1998 H18 SX sail #1330
Sandy Hook Bay Catamaran Club

Congratulations on your new boat! The Hobie 18 is a great boat, but not without it's challenges to get used to. Coming from a monohull, there are a few techniques that will be a little different. Tacking, for one, is a little more difficult on a catamaran because they don't have a lot of momentum to carry them through the tack. In order to get through the tack more quickly, racers have adopted a "roll tack" technique that helps the boat through the wind, by moving weight to the aft windward corner early in the tack, and then crossing to the forward crossbar on the new windward side just slightly after the boat crosses the wind. A book I would recommend for the nuances of sailing catamarans is "Catamaran Racing for the 90's." I thought it was well written for a sailor familiar with the basics, but new to catamarans. It also has a chapter specific to rigging and sailing the Hobie 18. Also, there is a booklet entitled "The Hobie 18 Performance Manual" which gives some great tips as to how to rig and sail the boat, including exactly what you're looking for, a guide to mast rake, mast rotation, diamond wire tension, etc, which can be bought from Murray's Sports.

With regards to your specific questions:

Upwind I tend to put my jib fairlead about 2/3rds the way back from the front and sheet it fairly tight, watching the telltales to keep them flowing and being careful not to close the slot between the main and the jib. The main of course is sheeted fairly tight. Best angle of attack seems to be with an apparent wind at around 35 degrees off the bow.

Downwind is tricky on a catamaran, because you want to sail a broad reach (it's faster than a run). For downwind sailing, I move my jib fairlead all the way forward, sheet the jib loose to leave an open slot, and try to keep the leeward telltale flowing (the windward one never flows well downwind). The main traveller is let out to about 6" from the inboard side of the leeward hull, or about in line with the hiking strap, and the mainsheet is almost loose enough to let the mainsail rest against the shroud. Again, watch the slot. Apparent wind should be exactly 90 degrees. Just like upwind sailing, there is a "groove" for downwind sailing that you want to try to maintain, by sailing a slight "S" course.

The "wishbone" you're asking about is the mast rotator. There should be a line going from an eye on the side of the boom, through the end of the rotator and then back through a jam cleat on the top of the boom. Pull the line tighter to allow less mast rotation (i.e. mast more fore-aft oriented), or let it out for more rotation. Less rotation = less mast bend, more sail shape & more power, more rotation = more mast bend, a flatter sail and less power. Generally, the idea is that the mast should be allowed to rotate about 70 degrees off CL (the rotator/wishbone should point at the leeward shroud) when sailing upwind and 90 degrees off downind, in order to give the mast & mainsail a smooth entry profile to the wind. In heavier winds, rotate more, in lighter winds, rotate less. If your diamond wires are looser, the rotation has more of an effect, and if they are tighter it has less of an effect (because they stiffen the mast on it's minor axis).

_________________
Mike

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

Welcome to the dark side. The 18 is a very versatile boat...good choice

Short answer...when close hauled to Weather, you can bring the jib all the way in. Watch the slot at head of jib, it is possible to backwind the Main.
Off the wind, release jib sheet tension, and/or move the jib car forward on its track.

Exactly, point it at the shroud (sidestay) for close hauled upwind. If all other depowering techniques fail (downhaul, main traveler out a bit) point it further aft.
Release to let mast rotate forward on downwind run

_________________
1984 H16 "Mister Rogers"
1984 H14 "Sundays"
2000 H20 "Jet"
Sheet In, Max Out

Thanks so much you guys for all the recommendations! Good books to read and a whole new sailing experience!
When I bought my sport boat I had to learn to sail all over again, now I get to again. It seems a sport boat is closer to a cat than it is to a non-planing mono haul? At least what I've read and watch they are somewhat similar. Thanks again.

[quote="Kaos"]First, welcome to the club. You selected a great all round boat. There are some good books out there that will give you plenty of information as you learn about the different adjustments to the boat. "catamaran Sailing from Start to Finish" by Phil Berman is a very good one, simple to understand.

Just ordered the book! Thanks, looking forward to it.

This is great info and all makes sense to try. I bought a small gps speedo to help see what settings are helping.
I come from a 25' sport boat and everything is different than most mono hauls.
We used a roll tack regularly in light air, traveler out reaching. There has been a lot of response about the slot effect. On my sport boat we were always looking to make the jib and main act like one big sail going hard to windward unless it was light and then we would loosen and open things up.
We were mostly just racing her so speed and pointing high were always the focus. I had in-haulers on the jib sheets to bring the jib in about 16" from the mast. We could point really high and maintain speed. Reaching was more near a cat, very fast planing!
So I was intrigued by the fact the you can naturally bring the jib in all you want. This will be fun to play with that, pointing and speed.
Thanks so much for the detailed reply! Steins

Check out the web page fleet297.org it gives sail tuning for most 18 components at all angles and wind condition. It's like a tuning cheat sheet.

For Xmas, have someone buy for you Higher Performance Sailing II, by Dr Frank Bethwaite.
Not cheap and over 1,000 pages. I read it quickly over Xmas one year, just to get the drift, then again in detail over New Years, and I often dip back in when I want to re-educate myself.
Apparent wind is your friend, and welcome to the Hobie world.
The Rick White video is also great, but there is nothing like 'time on the water'.

Happy Holidays

_________________
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.'