I had a Dotan system on my M 6.0. If you sail in an area where you can put them down and not worry about ever having to sail with them in the kicked up position I'd rate them a 4 on a scale to 10.

Some of the problems. When kicked and trying to steer they flex a lot. The rudder blades float so when they kick they raise so high as to make it impossible to steer. You don't want to be around me when that happens. ( I understand why they float) If you snug up the pivot screw you can stop this from happening but then they become difficult to operate. The screws that are part of the pivot mechanism bent. I also broke a rake adjusting screw when hitting the bottom. A lot of small parts.

my 0.02

Wouter:

Could you please tell who made a test on G-cat F16? Where is it possible to get more information about it?
Maybe you can recall 18HT sailors as well, it would be very interesting to get feedback directly from them.
Thank you!




catman:

Thank you for sharing the experience.
We assume that when person launches a cat, he mainly controls a boat with the sails(mainsail & jib). Rudders are used as a "steering helper" for sails. Finally, when the water is deep enough - sailor lowers the blades.

Rudder blade floats because it is very light. We consider the low weight as an advantage however, as many sailors are very much concerned about the weight of every boat part. Generally, we can put the lead inside in the bottom blade area. So rudders will be more suitable for leasure sailing.

Probably screws bent sometime after you tried to make some alterations in the setup(snug up the pivot point etc..) So after these alterations there were some freedom introduced between the rudder box and the blade. In this case, there is a very big chance that the screws will bend... Thus, it is strongly recommended not to make changes in the factory setup without asking for advise from the Dotan.
What rudders do you use now?
What will happen to them if you hit the bottom(like it was with Dotan rudder)?

Brett Moss and Hans Geissler

I think you can contact Hans via his website :

http://www.g-catmultihulls.com/

Wouter

Wouter:
This is an interesting thing to know...
Last time I heard about Hans Geissler he was going to race equipped with Dotan rudders.

Second thing is that Dotan rudder boxes have been used on G-Cat 21' during some time. So far there haven't been any problems reported about weak rudder boxes from the owner. Something makes me believe that rudder loads on G-cat 21 are higher than on G-cat 16.




I shall definitely try to get an update from them.

Friend,



Yes, they raced them on the new G-cat F16 and it was reported that they broke and proved to be not stiff enough. Now we can talk around these rudders for ever but the that doesn't change what happened.

I don't care much about what works on the G-cat 21. I think most of us are only interested in what works on F16's.

Now I'm not saying that the rudders are at fault here. I'm just relaying what reached my ears. Don't shoot the messenger, take this offline with Hans and Brett.

Wouter

Dotan,
In the picture you included in your post, which appears to be the aft end of a G-cat, the rudder looks to be tilted off center (gudgeons not aligned properly?). And, in addition to that, the the rudder blade itself appears to be twisted a bit from top to bottom.

Wouter:
There are 1000 and 1 reasons why the rudders break - negligence, skipper errors, improper "center of the lateral plane", defects in workmanship, weakness of the materials etc. If the problem is on our side, we would like to address this problem and solve it. Consequently.. in order to find out where the problem is, we have to get feedback from every sailor with such experience and analyze all the facts.



Mary:
You are right, as you can see in the photo, the rudder is tilted off-centre. However, there is not a problem with this and the gudgeons are aligned properly. This setup(when gudgeons are not centered) gives a small, positive effect when taking into consideration sailing at heel.
In this case it is very important to preserve rudder parallelism.

Without any doubt, the rudder blade is not twisted. It looks like an optical distortion or something like this.

uh-oh Hans is busted.

Dotan,
Can you explain what you mean by "rudder parallelism"?

Possibly rudder parallelism is not a good word.
When you cross the rudder blades in horizontal plane, rudder blade section chords(red lines on the photo) should be parallel between themselves.

I beleive that the ABA AMRO boats found that 2 degrees toe in on their rudders gave the best results, would this be the small for cats.

Wouter,

You arrogant pompous, lying scumbag.

I don't have a "deal" with anyone, certainly not YOU.
There is no "truce", or agreement or understanding.
I chose not to post because I was bored.
I will post on any forum I want to.
I will post about anything I want to.

Who do you think you are?
As we repeatly told you when Rick White first created this forum, YOU ARE NOT IS CHARGE.
This is not YOUR forum.
The people who choose to post here ARE NOT UNDER YOUR CONTROL.

Perhaps it is time I resumed posting.
The newbies should know the true history of you and the f16 "class".
Like how you stole a set of Taipan 4.9 plans, had a pair of hulls made with a few minor above the waterline changes and called it "YOUR" design.
You called it a tiafoon and never did pay the license fee to the real designer.


BRING IT ON !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Damn, its alive. And just because of something Zuhl posted. He hasn't posted here since Feb 13th, 2006. (Zuhl that is).

abuahuauhauhahuabuuauahahahahahah look whos back! LMAO! some one sponsor the popcorn! LOL

Maybe someone has found a way to post, using an existing forum members ID <img src="http://www.catsailor.com/forums/images/graemlins/grin.gif" alt="" />

Sam,
At Wouter's behest, I contacted AHPC about your charges, and Greg Goodall replied to me as follows:


I hope this sets the record straight.

OK I can take neither blame nor credit for this.
As to posting, I've been working on my monohull all year, Computer fritzy half the time.
Looking forward to seeing you guys at Spring Fever's 10th Anniversary this spring.
CARY
C&C 24 "Caliente"
SEACATS

OOOOOOOOOOOH!! so who is the liar now? <img src="http://www.catsailor.com/forums/images/graemlins/tongue.gif" alt="" /> I am sure Sam wont reply he has selective reading. <img src="http://www.catsailor.com/forums/images/graemlins/grin.gif" alt="" />

Ill be waiting for the nasty private message Sam. You know how I do it, I am your crying shoulder <img src="http://www.catsailor.com/forums/images/graemlins/tongue.gif" alt="" />




ps: I love this forum. Nothing like reading good ol fashion Hobie bashing, Nacra greatness, fad boats and how the polynesians found land by reading wave intervals <img src="http://www.catsailor.com/forums/images/graemlins/wink.gif" alt="" />

So Cary, long time no type.

Are you denying trying to stir up a little trouble? It just took a little longer than you figured.

<img src="http://www.catsailor.com/forums/images/graemlins/grin.gif" alt="" />