Wind Gusts: AI Turns Into the Wind, Loss of Rudder Control…

When sailing on days when the wind delivers sudden heavy gusts, my AI turns into the wind. I’m used to that, and can usually correct for by turning the rudder control in the opposite direction to maintain proper heading.

However, lately I’m finding this technique no longer works. I find myself sailing into the direction of the wind, unable to regain control until the wind gust has subsided somewhat. Even if I bring the rudder control over ~45 degrees the opposite direction, there is no rudder response. When I check the rudder steering control lines, all looks fine… there is no slack, no slop in the line and I’m able to observe an instant change in direction when using the rudder control lever. It’s like the control lines turn into a rubber band during heavy use. Any Idea if this can be fixed somehow? Oh yeah, guess I should mention that the rudder >> is << cleated down when this happens.

My AI is a ’09 with the newer Up/Down T-Pull handles

_________________
'09 Yellah-Colored Adventure Island (single seater, with room for me and all my friends)

Do a search for more information. This has been discussed may times. You have to reef the sail in some conditions. The dagger board and fin positions also relate to control issues.

http://www.hobiecat.com/community/search.php

Result example:

http://www.hobiecat.com/community/viewtopic.php?f=71&t=8925&hilit=reef+rudder+control

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

Thanks Matt,

So, let the sail out a little, regain some rudder control and then go even faster??? Say it ain't true... This Adventure Island thing is pretty cool indeed!

_________________
'09 Yellah-Colored Adventure Island (single seater, with room for me and all my friends)

If the wind speed has increased, you need to reef the sail (roll up), to make the sail a little smaller.

If it's just gusts, letting the sheet line out a little releases some wind from the sail.
In gusty conditions, I don't lock my sheet line, but hold it with my arm up, so any gusts pull my arm down some to even out the gusts.

Always fun to play with the AI to learn what works for you and your conditions.

_________________

Hobie Island Sailing since 2006

I had a lot of problems with getting over powered by the wind while keeping a full sail out. This problem inspired me to take a whole series of sailing lessons here on the SF Bay. I have learned as the wind speed increases you haul in the sail "reefing" to match the wind conditions. This over powering and loss of rudder control occurs on all size boats, not just Hobie's. As the wind increases you need to reef the sail to match the wind speed, this will allow you to sail faster with rudder control and for gusts Kayaking Bob is right on with just letting the sail out to dump some wind and depower the sail.

Leaf-Peeper, the reason the AI turns into the wind is that the center of lateral resistance is too far farward of the center of force. Several things can help fix this problem. First make sure the rudder is cleated down. If not it will simply kick up and have no effect. Second you can remove the mirage drive and put the plug in. This will remove much of the too far forward lateral resistance.

If you don't want to remove the mirage drive then make sure it offers little lateral resistance by pushing one pedal all the way forward, spreading the fins against the bottom of the hull. Also you may let the centerboard fold all the way back. This will put the center of lateral resistance a little further back.

The last and most dramatic thing you can do is reef the sail. This will put the center of force further forward. I never do this however because I have found it is not necessarhy and cost me speed. I never sail with the mirage drive in except leaving and arriving at the launch area. The difference in speed with the drive out is very significant.

Some claim that they can go faster if the reef the sail. This is true but only because they have to hold such a hard rudder that the rudder drag slows them down. Removing the mirage drive and folding the centerboard back will make a hard rudder unnecessary.

Ron Patterson

Actually, the fact is that the Adventure is one of only a few sailboats that allows you to keep sailing in strong air, at any pace you want, by reefing in the sail while sailing if it starts becomming less rudder responsive. That is one of the reasons this is such a great boat! Take my nacra for instance: yes it can sail in heavy air but guess what- it's alot of work and requires constant corrections to keep from crashing and burning, because I cannot reef the sail. Last weekend after sailing the Adventure for a few hours in heavy air I decided to take a break and just fully reefed and sailed casually down wind with just the pole, then after a nice little break, fured her out and sailed back. Another comment about speed and bow plowing: Look guys, if you want to go fast, buy a jet ski, or better yet a catamaran. The Adventure is designed for casual fun, not racing speed, and I can rig and de-rig in 15 minutes. It's the best sailboat ever for what it is designed to do- bring a big relaxing smile to your face after a long stressful work week!

_________________
Sail it or Sell it.

If we are talking about sailing DOWNWIND in strong winds, my technique is to maximise slip by removing the dagger-board and ensuring the mirage fins are horizontal, then sail full sail keeping a sharp eye not to run into the back of the wave in front. Be very mindful of possible broaching and correct any tendancy before that happens and you lose control of boat and subsequent steerage. To my thinking they sail very well down-wind under full sail so long as you remain vigilant to signs of broaching. I have found the AI a very safe and fun boat under those sorts of conditions...Pirate

_________________
Master of the galleon 'Pirates Lot'

If I secure the rudder down with the screw and remove the mirage drive, I almost never have weather helm issues.

_________________
jzk

Hobie Adventure Island.

[youtube]http://www.youtube.com/watch?v=pTIq7IhU84Y[/youtube]

That's because you're side-slipping so much it stops the weather helm.

_________________

Hobie Island Sailing since 2006

What makes you think I am overly "side-slipping?" I have the daggerboard down. The boat is sailing great. The only reason to furl is to prevent the leward ama from burying itself. With the tramps, I almost never have to furl if I hike out.

Weather helm is caused by the boat not being balanced properly.

_________________
jzk

Hobie Adventure Island.

[youtube]http://www.youtube.com/watch?v=pTIq7IhU84Y[/youtube]

Exactly! I have been sailing for many years but only started sailing the AI this year. It was obvious to me from day one that the AI is very unbalanced with the mirage drive in. A boat must be balanced. If your center of force is aft of the center of lateral resistance you will have a strong tendency to nose into the wind. This creates a strong weather helm in an attempt to compensate. And this weather helm will create a lot of drag, slowing you down. This is nothing more than physics 101. If you balance the boat with full sail, you can have maximum speed.

With the centerboard folded back and the mirage drive removed the AI is near balanced. You will have just as much, actually slightly more, centerboard in the water when it is floded back and have very little sideslip.

Ron Patterson

Hmmm, interesting! I have been wrestling with the question of the how's and why's of the Daggerboard and Mirage drive up, down, at 45 degrees, in or out?
I have always assumed (maybe incorrectly?) that the centre board provides the pivot point that the boat uses to steer around. With the dagger board up and facing backwards, it is now a long way back from the mast and will make the boat harder to turn, which presumably has the effect of reducing the leverage the rudder has over the boat and increases the leverage the mast and hull forward of the mast can exert? I also assume that with the daggerboard horizontal, it will make the boat less maneuverable but may track in a straight line better, depending on angle to the wind?

_________________
Either lead, follow, or get the hell out of the way!

That is pretty close. The rudder actually pushes the stern of the boat around and it usually pivots around the center of resistance.



This is where you go wrong. It doesn't matter where the mast is, what matters is where the center of force is. The AI has a sail area of 57.5 square feet. If you could pick a vertical line where 28.75 square feet of sail was forward of that line and a point where 28.75 feet was aft, that would be the center of force. The boat would perform best if the center of lateral resistance were directly below that line. That is the point you should be concerned with, not where the mast is. Of course you can never get the boat perfectly balanced because the angle of the sail will move the center of force slightly forward or aft.

It makes little difference if the centerboard is up or folded back, the boat will steer just as well either way. With the mirage drive out and the dagger board straight down, the center of lateral resistance is still about a foot or so forward of the center of lateral resistance. Folding the centerboard back puts the center of lateral resistance about a foot further back and puts the boat in very good balance.



Any difference would so slight it would be impossible to detect.

But you are worrying about the wrong thing. Worry about balancing your boat, or kayak in this case. If your AI is not balanced, with the center of lateral resistance way forward of the center of force you will have to hold a constant weather helm to make the boat go straight. In very strong winds this could be as much as a 35 degree angle. This will act like a brake on your boat. If you don’t believe me just hold the paddle in the water at a 35 degree angle and see how much it slows you down.

Ron Patterson

Thanks for the clarification. I will experiment with the new info this weekend. I had assumed that the force would be greatest where the mast connects it all to the hull.
Based on your explanation, the answer could be to move the mast forward, perhaps to the back of the front hatch?
It wouldn't be too difficult to knock up a temporary setup to test the theory.

Presumably there would be other side effects doing this, for example would it be more prone to bury its nose downwind, if everything was moved forward?

Going on further with your suggestion, presumably with the sail straight back (well as far back as it will work when pointing), the force is furthest back on the hull. As the sail is let out the force presumably moves forward and sideways?

_________________
Either lead, follow, or get the hell out of the way!