Today was the second day out. The first day was a rather relaxed 3 knots, nice and cruzzy for a couple of guys that really have very little idea about how to sail a 14 ft catamaran (14 ft Maricat) very similar to a hobie-turbo with Jib-sail etc. That day went rather well, we had 4 hours of just meandering around.
Though today was a whole different story of hardcore excitement and action. 8 knots gusting to 15 - 20 knots. Me being the Helmsman?, I had control of the Mainsail, rudder, and my mate (crew) had control of the jib. I had no idea these things took off as fast as they do in a bit of wind.
One thing I noticed was the rudders wanted to turn into the wind, it was a real strain to keep the little Maricat on a straight course, I believe this is called "weather-helm"??. We were close-hauled heading very close to the wind I thought, and like I said, it was a strain to hold the rudders straight - Is it supposed to be a struggle?, if it is then thats all cool, but if its supposed to be easier that would be better, by a "strain" I mean I was hanging onto the tiller with enough force to give me cramp in my hand and arm.
I checked the alingment of the rudders while I have been practicing solo-rigging at home in the backyard. I line the port side rudder up with the stay-thingy up on the bow, and check the starboard side, it seems the starboard side has a very slight "toe in", maybe 10 - 20mm. Also I noticed the rudders are on a bit of a camber' ie: the bottoms of the rudders are a greater distance apart compared to the top of the rudders, maybe as much as 150 - 200mm. Could either of these things be contributing to my cramp/white-knuckle hold-on-for-dear-life steering system?
Regarding the "Amature Sailors" we couldnt tack!, i'm convinced it was because my crew was kooking it with the jib sheets, We had untold speed on and I'd call for the tack, turn the rudders so we flew into the wind, then we would just stall and the bow would get pushed back around to the way we just came from (close hauled) and have to continue on the same course - Toward the rocks!.
Knowing I had to do something drastic to avoid a nasty collision I called for us to turn downwind at speed - The result was a spectacular pitchpole, a bit of a concern being upside down but it was rather easy to get it back on its feet again.
I think we need a book or something?. Actually it was such a buzz and as soon as we left the boatramp it was all on, I didnt even have time to do up my wetty, it was only half on the whole time.
Any help would be appreciated, espessialy regarding a book that will explain in simple terms the workings of a small catamaran for beginners, it would be kinda nice to get over this beginner stage so as the local boaties dont see us and shake their heads and say to each other over the VHF "Oh man, watch out everybody, here comes those 2 guys on the blue catamaran again - Keep an eye out for them will you!".
Yes. You need a book. Start with downloading Hobie University, and at the same time, order a copy of Rick and Mary's "Catamaran Racing: For the nineties" available on the shopping section of this site. You have a bit too much weather helm; the instant fix is to leave the jib in tight while easing the mainsail. The actual fixes: if your rudders are travelling at less than about 4 degrees angle to the water, they need to be raked forward, so that the bottom tips of the blades are more under the boat. This will lessen helm feel, sort of a power steering effect, but will not change the angle of attack that the rudders have to the water. The next thing you can do is rake the mast forward, admittedly not usually a good plan when it's windy.
I have read that people "kick the rudders under" but never understood why - Now I know i'll do it this week.
I'm not sure I want to rake the mast forward, I have been told to rake the mast back to about level or near to the back beam. But I have read information about hobiecats that suggests this makes tacking even more of a nightmare.
As it was yesterday, the mast had a nice big concave in it from holding that wind anyway, and probaly was rather close to the back beam with the curve. I have it raked a little, probaly about 600mm off centre (or mast being horizontal) toward the back of the boat. I have read that a raked mast will carry the wind higher up in the sail?, and I dont know if i'm ready for that yet! LOL.
Cheers for the hobie-university link, its a massive file so should hold some great information.
No worries about sailing fast - That was the whole idea, i'd have loved to see a video of our pitchpole, thats the most exciting thing i've done since sliding 50 meters on blue ice toward a bluff.
We're both totally stoked on it and will be laughing at it for ages, another good thing I noticed was the willingness to help by the other boaties, some big gin palace rocked over to ask if we wanted a tow, I was temted just because of the state of this amazing 'palace on the water' (I was getting hungry too, and they looked like they had food!).
Regarding the "Amature Sailors" we couldnt tack!, i'm convinced it was because my crew was kooking it with the jib sheets, We had untold speed on and I'd call for the tack, turn the rudders so we flew into the wind, then we would just stall and the bow would get pushed back around to the way we just came from (close hauled) and have to continue on the same course - Toward the rocks!.
Deja vu. My wife and I just started last year and had the same problem.
The book to read on this is Rick and Mary White's Catamaran Racing for the 90s.
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Knowing I had to do something drastic to avoid a nasty collision I called for us to turn downwind at speed - The result was a spectacular pitchpole, a bit of a concern being upside down but it was rather easy to get it back on its feet again.
The pitchpole is not really recommended, from what I understand ;->
Seriously, if you first go to a beam reach, then head a bit further downwind, but not directly downwind, you can then do the jibe a lot more safely from that position. I guess I go to a straight beam reach first (90 degrees), then to about half-way between that and straight downwind (135 degrees or so), before I actually do the jibe.
But I'm also a rank beginner, and others here may have better advice for you.
The pitchpole is not really recommended, from what I understand ;->
I disagree, the pitchpole is a lot of fun, though my crew obstructed the view of (as the crew said it) "Man we titaniced up the front, man, we just went down".
I am actually glad that it happened to us when it did as, we hadnt talked about how to right the boat, I had read up on how to do it in these forums somewhere, from turtle to sailing was about 6 minutes?.
Next time i'm just gonna swim under that hull and grab a hold of that righting rope though. No mucking around "woohooing" in the water.
with the boat on the trailer or in the dry and elevated somehow, get the rudders pointed straight and have them deployed pointing downward like would be normal under sail. Measure the distance between the trailing edges of both rudders and then measure the distance between the leading edges of both rudders. The measurement should be about the same (some say 10mm of toe in is good - this means the leading edge measurement would be 10mm less than the trailing edge). Be sure your measurement points are taken at the same elevation in the blade - especially since yours sound like they are cambered outward (which is not a bad thing). To test if your weather helm is because of your rudder alignment, raise the windward rudder while sailing next time. If your helm goes away it's rudders. If it doesn't, it's probably a sail related problem.
Excessive weather helm is usually caused by an imbalance in the sailplan. Two forces are working here - the sails trying to pull the boat in a nearly sideways direction, and the hulls (and centerboards if you have them) grabbing into the water resisting that sideways force. The result is forward motion. However, if the center of lift in your sails is behind the center of lift of your hulls it will be unbalanced and the boat will want to pivot and turn. Your mast rake plays a large part in this because it will tilt your sailplan forward or backward and move the center of lift of the sails accordingly. If you are experiencing too much weather helm, and your rudders are aligned properly, rake your mast farther forward. A little weather helm is a good thing from a performance standpoint and a safety standpoint. You CAN rake your rudders farther forward to reduce the pressure you have to apply to keep the boat straight but this does NOT fix weather helm - it only aligns the center of lift of the rudders closer to their pivot point and gives you more mechanical advantage.
All this and a LOT more is in Rick's book - I highly recommend it.
First realize that the boards and rudders are essentially the same thing just in a different location. They both share the load from the sail plan. How much load is on each of them depends on the position of the sail plan in relationship to the foils. When you move the sail plan aft (more rake), the rudders begin to carry more load.
Getting the balance right between weather/neutral/lee helm is not an issue of right or wrong for the sail plan. Adjust the rig/sails for max performance. Then once you know where your rig needs to be, you adjust the rudders to match that setting.
As you rake the mast aft, the rudders begin to carry more load. What you feel in the helm as weather or lee helm is simply an issue of imbalance. If the boards are carrying 70% of the total from the main, then the rudders would be carrying the remaining 30% (assume 0% for the hull to simplify argument).
The total quantity of lift for the entire board can be averaged and assumed to come from one spot on the board, the CL(center of lift). The lift from the foil and from the sails can all be assumed to be concentrated on this point (one for each of the sails and boards). The rudder is the only one that you notice a change in because it is the only one that pivots and we are directly connected to.
Here is where the balance comes in. The quantity of lift and it's relationship to the piviot point of the rudder is why you feel weather or lee helm. It isn't an issue of more leverage against the rudders. It is that the CL is either too far forward or aft of the pivot point of the rudder. As the rudder is raked, the loading does not go away, it is however carried by a different part of the boat. Instead of being translated to the skipper and him/her haveing to pull on the stick to keep the rudders straight, the pin is now carrying the lateral load and is experienceing more sheer stress. You have simply found the point where the CL is aligned with the rudder pin and the forces balance.
On additonal thought...it is in a way a leverage issue. By raking the rudders forward, you decrease the leverage the rudders have on you (shorten the distance between the CL and the pivot). This is a fix for weather helm, so long as you are not having to keep the rudders turned to keep the boat going straight.
Thats all great advice, i've bought an old "learn to sail" book that has a lot of info on weather/lee helm and am understanding the balance of the sails/rudder more now.
I'll rake the rudders and trial it, if I think its needs improving more i'll rake the mast forward a notch. The thing is that the aft stays are attached at the very top ring of the brindle-thingame-whatsit. I might have to go get a longer set - Or do you think a grunty shackle would do the job?.
I stand corrected - raking the rudders will eliminate or reduce (or even make negative) the tendency of the boat to round up into the wind...i.e. "weather helm". What I should have said, as Will put it, that raking the rudders does not change the amount of load on the foils under the water but only the amount of it you feel.
P.S. If you rake the rudders too much, you'll get lee helm and this is bad. With lee helm the boat will be turn downwind and sail away if you fall off.
P.S. If you rake the rudders too much, you'll get lee helm and this is bad. With lee helm the boat will be turn downwind and sail away if you fall off.
Ahhhhh, so I should maybe just rake the rudders forward perhaps 10mm at a time?, go out and sail to see what changes have been made, and if it still feels heavy, rake them forward another 10mm?.
That way I can get the weatherhelm to not feel so dramatic?, I understand wanting a little weatherhelm so as the boat will turn [safely] into the wind when I let go of the tiller.
Does this mean I could further rake my mast back, and increase the rake of the rudders forward to counteract the effects of raking the mast back?.
Re: Weather-helm, and amature sailors.
[Re: sonicassassin]
#19670 05/21/0302:22 AM05/21/0302:22 AM
The problem is best overcome on a Maricat by rotating your rudders under the hulls so the corner of the bottom of the leading [forward] edge is about 50mm forward from perpendicular. This will kick them under the hulls.
You can get all the tips for you boat if you look upthe tuning & FAQ link on the Maricat Asociations web page. It spell it out what you can do step by step
You can get all the tips for you boat if you look up the tuning & FAQ link on the Maricat Asociations web page. It spell it out what you can do step by step
Cheers Inland, and I did look there, but it was such a tiny bit of information I thought i'd ask here as well, as it turns out most of the replies suggest raking the rudders forward as did that site.
I'm reluctant to attack my rudders with a file/rasp/disc grinder simply because it was suggested to do so in a paragraph on a website.
Always best to see what others with experience have to say - I guess i'm paranoid and dont trust everything I see, not such a bad thing when the cost of these boating bits are so expencive.
I have a fairly large spinnaker that I occasionally use with my Nacra 5.5SL.
When the wind picks up beyond a light breeze it gets quite a bit of lee helm (ie I have to push on the tiller to keep on course and not get blown to far down wind)
So my understading is I should 1) Rake mast back 2) Move rudder toe back
Is this Correct?
Of course this then messes up my upwind and non spinnaker handling. But basically the boat was not designed for a spinnaker and the spinnaker I have is to big for this boat. But I got it used for a good price so I am not complaining. Anyone want to trade a 225-230 sqft spi for a 300 sqft spi in good condition?
There's no need to attack your rudders with a rasp or file unless you only need say a 10mm adjustment.
They are best altered by removing your rudders by unbolting them and then drilling a second hole off centre in the rudder.
To find the spot. hold your rudder at the desired angle next to the rudder housing. IE parallel with the rudder box, in the "down" position as if your boat was in the water. Mark the spot with a marker through the bolt hole that the rudder pivots. [That's probably off centre by 3 - 5 cm] Drill the rudder[s] at this position and put it all back together again, using the newly drilled holes. Then any minor adjustment can be made using your rasp etc
They are best altered by removing your rudders by unbolting them and then drilling a second hole off centre in the rudder.
To find the spot. hold your rudder at the desired angle next to the rudder housing. IE parallel with the rudder box, in the "down" position as if your boat was in the water. Mark the spot with a marker through the bolt hole that the rudder pivots. [That's probably off centre by 3 - 5 cm] Drill the rudder[s] at this position and put it all back together again, using the newly drilled holes. Then any minor adjustment can be made using your rasp etc
OK, that seems like a more reasonable alternative to filing my rudders, I have attached a diagram just to ensure I understand correctly.
The angle is probaly a little exagerated, but I'll adjust the rudders to rake 50mm forward of horizontal/level as per the maricat association website, on the understanding that this will releive the helm "feel", if per chance I should have Lee Helm after this adjustment, I can further rake my mast back a notch to correct this back to a slight Weather Helm "feel".
My mast can be further raked aft as there is adjustment to do so on the side stays. As the mast setup is at the moment there is no forward adjustment left on the side stays so as to have a vertical mast, or less rake than what I have at the moment ie: 600mm aft.
I hope thats not to confusing.
Last edited by sonicassassin; 05/21/0306:24 PM.
Re: Lee-helm with Spinnaker
[Re: PRagen]
#19676 05/21/0309:49 PM05/21/0309:49 PM
I wish I'd known you six months ago! I sold a 221 sq ft chute because it just wasn't quite enough grunt for my P-19 with around 400 lbs crew, and bought a near New England-class Nacra 6.O chute @ 346 sq. ft...it's a bit big tho. I'm running it on a 15' 4" pole and still sheeting to the rear beam...you just THINK your 5.5 has lee helm when it gets reachy and breezy! Anyway, email John Howard; he has my old sail on his P-19, and might want to trade up to the boat's "correct" size of just under 300 sq. ft. Try JHoward@CFNTEXAS.com
I did what was suggested, and everything is now perfect. The helm "feel" is much much more managable and a hell of a lot more comfortable.
I was even able to rake my mask further aft as I went out for a quick test, came back in and adjusted, went back out and things were all cool - Though I am still unsure of the advantages/disadvantages of the raked mast, I guess I will find out, it didnt seem to make much noticable difference, I guess I was just stoked on the easier steering.
Tacking was a little sketchy as I was out by myself, but I took the opportunity to get in and out of Irons and fully sort that out.
Am a little bit paranoid about capsizing alone as I dont know how hard it will be to solo-right. I'll take my mate out again and capsize on purpose and try solo-righting. I think he's a bit chicken after the pitchpole incident though.
