Optimum Downwind (Broad Reach) Course

How do you know the optimum course (apparent wind) when doing a series of broad reaches towards a downwind mark? I have a Hobie 18 and am obviously still learning a lot. I have a Davis Telocat mounted up front. Do I want the apparent wind at 90 degrees to my course, or "it depends"? Please help!

Thanks,

Mark

90° apparent is about 120° true off the wind, at about 10 knots boatspeed. optimum downwind angle is as far as you can get downwind without sacrificing speed. if you can carry max speed at 135° downwind angle you are way ahead of the game. it helps to have a compass onboard to compare speed and angle. of course you should have calculated course direction before the start of a race, which is compass direction from the start line to the upwind mark, adding any wind direction variation.

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Chris
'88 H18SE Arís

About 90 degrees apparant wind will get you in the ballpark. Slightly deeper for light wind and possibly slightly higher in high wind (upper teens or greater). One of the most critical things is to have the crew work the jib constantly to keep the telltails flowing throughout your steering and the apparant wind directional changes. Allowing the jib to stall (leeward side telltails flowing up or forward) even briefly is very slow.

Getting the boat pointed in the right direction is pretty easy, but taking advantage of the subtle wind changes is what separates the top guys from the rest of the fleet. A lot of this comes from experience and watching/racing against other boats.

sm

Boy is this is the thread for me. Coming from a background of Flying Scot sailing (DDW with a spin - no comments mb), I have to say I have really struggled this year with my H18. Upwind - I still have much to learn but feel I am making solid progress, but downwind, well...

The first problem is that I'm sailing Portsmouth with no other H18s. It's impossible to judge relative depth of reach, what works better, etc. I've tried various strategies, but at the end of the day all I can do is look at the corrected times and see that I'm still getting crushed.

The second is translating the theoretical book knowledge into practice. How much should you heat it up before bearing off? How does that change as a function of wind speed? How does sail trim factor into it. etc, etc.

I realize the answer is probably simple, and one that I won't like ('cause its not an easy fix): like any other sports its got to be more boat time in a competitive setting. Something that's difficult when you live in MI, only have 5-6 regattas a year, and nobody else in the same class to sail against.

So, a couple of specifics to start: Sail trim. I have read in multiple locations and assume that as a starting point the main traveler should be 4-6" inside the leeward hull and the main sheeted out so the top is twisting off (not too much) so it's barely touching the shrouds. Based on this, a few options run through my mind:
a) Does one set the jib relative to the main (so the tell-tales break similarly), and then steer for proper tell-tail flow, or
b) do you hold a course and adjust the sails to the wind? Or
c) does one sail the main telltails, while the crew adjusts the jib? or
d) ???

Sorry for the long and convoluted post. As my CRAM friends will vouch, this has been vexing me for quite some time. Your advice is much appreciated.

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Jeff R
'88 H18 Jolly Mon
'10 F18 Closely Called
cramsailing.com

Don't rely on my racing results.....

1. Be absolutely vigilant about your boat trim. (The fore-and-aft balance of the H18). The more you can have weight forward, the more the sterns will be out of the water and you will enjoy less drag. Easy to say....as once you pick up speed beyond about 5 knots, you need to keep the H18 flat, so move more toward the stern. In lighter winds, with flatter water, I have even laid out on the leeward hull in front of the cross bar, while the skipper helmed from the centre of the tramp. In 10 knots of wind, that's asking for disaster.

2. When the winds pick up, you can fly a hull if you want. About 2" out of the water is good. Anything more, and you will lose efficiency.

3. Most of the time, we will keep the main traveler within 4" - 6" of the centre line. Sheet in harder on the main as you speed up. (see apparent wind below).

4. Light winds = loose sail (downhaul, outhaul and rotator). That builds more 'lift'. Tighten up as you speed up. When you go over 15 kts of wind, loosen off again to depower, right SRM?

5. Jib, we usually set and forget, except for tacks and gybes.

6. What SRM said about tacking is critical. The crew should watch Rick White's DVD. Rick's lesson on tacking is awesome, the way the crew has to allow the jib to begin to backwind, and then keep its shape as the crew lets the jib move across to the other side. Let the jib keep working all the time to help pull the boat around,and not lose speed.
7. Headers and lifters....or gusts....as SRM said, learn to read them and use them, you can pick up 2 or 3 or 6 boat lengths in a flash.
8. Keep the boat steady...every time you or your crew jump around to adjust this or adjust that...you upset the trim of the Hobie and you slow down. Move quietly when you do move and settle down quickly and re-trim.
8. Practice, practice, practice, and have fun.
9. Borrow or buy Higher Performance Sailing II, by Frank Bethwaite. (Father of the World Champion in Aussie 18 Skiffs.) Then you'll really understand apparent wind.
We're lucky enough to have three sets of weekly races in Ottawa. Tues at KSC, Weds at NSC/Brittania, and Sundays at LDSC, each about 3 miles apart. Club races are where you train for regattas. Hope this helps.

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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.'

Not much experience on the 18, but on the 16 it's all about the jib, apparent wind, and VMG. Here's what I do in general....

Travel out (both sails) max. Let out main sheet ~3 feet until main touches shroud. Let out jib sheet until you get flow on leeward telltales while holding a course to 90 apparent. Find the sweet spot and leave the sails alone....head up in the lifts and fall off in the headers. Steer smoothly and slowly...if you fall off too much, you'll stall the jib, slow down, apparent wind moves back, and you have to head up to heat up again. Main tell tells don't really work....steer by jib tell tales (just keep backside flowing).

I use cassette tape on the bridles, and usually try to keep them just forward of 90 apparent. You will go faster if you head higher, but you'll win more races if you sail as deep as possible w/o stalling the jib. In a puff you get more boat speed, apparent wind moves forward (velocity header), and you can bear off....smoothly and slowly. If you find yourself in a persistent lift, jibe. I jibe a lot more than I tack....not much time is lost when well executed.

You can lift the windward rudder to reduce drag. Correct me if I'm wrong 18 sailors, but I assume you raise the boards at least some to reduce drag and let the boat slip to leeward?

If waves are significant, you bear off when surfing (speeding up) down one wave and head up for power to climb the next. This is very difficult to master the timing on...you sort of have to anticipate the course correction before it's obvious or else you stay out of sync.

In my opinion, broad reaching is the easiest to learn to sail, but the most difficult to learn to sail well. It is difficult when you don't have a comparable boat to sail along with, but in general I've done much better sailing higher to windward (just short of luffing) and lower to leeward (just short of stalling). Not a lot of fun really....lower boat speed....but better VMG.

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Jerome Vaughan
Hobie 16

Fastest downwind is always by feel, and rarely in a straight line. Learn to watch the water for puffs, and not a wind indicator. Only when the wind is steady, and the water flat (almost never), would you just go in a straight line.

Add to what Jerome said.....you can raise the daggers especially the leeward, and also the leeward rudder if you want, less drag.

Try 135 degrees to the actual wind, and 'feel' it from there.
More a series of S bends, sort of, than a straight line.

We've also used the waves to 'surf' ahead, when we can.

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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.'

Just reversed I believe. Leeward is the lee / downwind side of the boat.

Windward... You can raise the windward rudder and dagger. You can partially raise the leeward dagger, but you need the leeward rudder in the water.

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

Oops, embarrassing typo, glad MM reads these posts.

_________________
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.'