Gemini Catamaran Rudder Line Replacement- June 2016

Gemini catamarans, of the 105 series have rudders which can be lifted by pulling on lines.  Lines also pull them back into place and hold them via friction clutch. A frayed line means failure is not long coming.

Frayed equals NOT GOOD

Frayed equals NOT GOOD

Since Yacht A Fun had already been hauled and blocked for drive leg repair and bottom paint work, maximizing the boat yard stay meant changing the rudder lines.  BUT— that meant dropping the rudders from their pivot tube to access the up-haul knot.

2 pivot tube Yacht A Fun Catamaran

3 connections Yacht A Fun Catamaran

If you followed our Gemini catamaran’s blog back when our steering failed in St. Augustine mooring field, you know that we replaced the steering cables.  To drop the rudders, we had to undo the steering cable’s insertion into the pivot tubes!  Well, at least I knew the needed process.

4 connections Yacht A Fun Catamaran


5 connections Yacht A Fun Catamaran

Dropping the rudders was really pretty easy.  Gravity is a great helper in dropping things.  Diann pushed the pivot tube out of its hull mount while I lifted on the rudder.  Thinking that “jiggling” the thirty pound rudder would aid her effort, I managed to slightly crush the threaded end of the port tube as it edged out of the hull socket.

A new tube is $65 plus shipping.  Thank goodness a hose coupling part for $1.78 was available to insert into the tube and by pounding would round the tube again.  Care had to be taken to not enlarge the roundness.

6 spreader Yacht A Fun Catamaran

7 tap Yacht A Fun Catamaran

One seldom enters a boat repair / maintenance item without finding some ancillary aspect which also needs attention.  That too occurred with the line replacement.  The rudder pivot circle which rotates on the hull mounted tube- had worn and lost chips of what appeared to have been a thick application of gelcoat .  The walls of the rudder box had lost some gelcoat- perhaps from oyster shell removal. (Yes, one needs to keep the rudder box clear of growing shell fish!)

Mixing West System epoxy and creating peanut butter consistency filler has become a new craft for Diann and me.  The maintenance was straight forward.

Once the maintenance was completed, bottom paint was added in the same sequence as for the boat bottom.

7 hung Yacht A Fun Catamaran

First coat, of two was Trinidad SR red

First coat, of two was Trinidad SR red

The 1” by 2” furring strips served well to create a lifting gantry for pulling the rudders back into place.

Painted with black Petit Trinidad SR & positioned for insertion up the rudder box

Painted with black Petit Trinidad SR & positioned for insertion up the rudder box

10 gantry Yacht A Fun Catamaran

By using extra line to create a fish-line to pull the newly attached up and down haul lines into their needed positions, we completed the job.

Having seen the frayed haul line, it made sense to check the haul lines for the two centerboards. And that leads us to the next item for maintenance……………

The story / blog of Yacht A Fun, a Gemini catamaran sailboat, traveling the ICW and east coast with insights to the extended cruising life. Rudder line replacement

Comments 7

  1. Enjoying your blog. Thanks for the tips on rudder removal – it’s on the list. Also in the process of repairing our wood centerboard (1999 M #651, Second Draft). Had some damage from groundings and some from scraping barnacles/wet wood. I’m not great at posting regularly, but if you want to check out our blog please feel free. We are also primarily Florida east coast sailors and are currently in Titusville. Fair winds.

  2. Hello sir,
    I apologize for disturbing you, but I have a big problem with a 105Mc Gemini rudder, and I’ve seen your website.
    The rudder on the right is broken in two.
    (I use a translator)
    And, I can not find a spare parts store on the Web for Gemini. (It’s very annoying)
    I am French and my boat is in Martinique.
    Would you have a store address? It would do me a great service if you do not mind.

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      I am unaware of parts availability for the rudder. Performance Cruising, the builder, is no longer in business. Catalina Yachts is building a greatly revised version of the Gemini. One suggestion is to drop the good rudder and use it as a pattern for custom construction of a replacement for the one that’s broken- if you have lost part of the one broken.

      I contacted, which is the company which brokers the current models of the Gemini. They were very responsive to point me on to The service tech there (Alex) was not in. His contact info is and phone 954-522-1114

      Hope this info does the trick for you…………

      1. Thanks Alex for your explanations.
        It’s annoying not to have a spare part, knowing that the system of descent and reassembly is broken in two, in the wrong place, just at the corner.
        I discovered that it was all composite (fibberglass).
        Not easy for a repair, the connection is small, and in addition there is the hole for the passage of the climbing rope.
        I am demoralised.

  3. For those interested? I hade a broken rudder on me 05/105. I live in Florida. Had a new ridder made at Foss Fome (?) in central fL. They now have all the forms made to make a complete rudder. They should be able to make with a phone call.

    Hope that help.

    757 717-6699

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