Adjustable rudders

Can one make a rudder you can adjust deeper or shallower (like a daggerboard) ?

I know you get some that swivel aftward like when they get hooked onto something but I'm thinking up and down...

The advantage would be twofold - you can have a smaller rudder in shallows, and it could be easy to replace a rudder in case one gets damaged.

 

Sure, my first foiler had one(same one on my new boat as well) ;so do the Bladeriders, RS600FF foilers and some beachcats...

 

Retractable rudderboards

 

You sure that thing floats Dough

I have seen those foils on some boats, but never had the oportunity to experience them for myself.

Do they make a big difference ?

 

A search on the forum and googling for 'retractable rudderboards' came up with no results

Does this not exist then ?

 

Maybe I'm not understanding you. The reason I posted the picture of my rudder was because the rudder blade retracts vertically in a "trunk" similar to
a daggerboard trunk. Same on the other boats I mentioned. A line can be rigged to retract the rudder from the cockpit or lower it from the cockpit.
The picture of my rudder shows it about 60% retracted. The reason you see this system on some boats with t-foils is because a pivoting system for a t-foil is extremely complex.
If by "rudderboard" you mean "rudderblade" then that is what retracts in the systems I'm talking about.
Hope that helps.

 

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Rudder t-foils work well on some boats; see this thread:
http://www.boatdesign.net/forums/showthread.php?t=22262&page=2

 

They are pretty commonly used on dinghies and trailerable boats because pintle and gugeon rudders can be tricky to attach in waves.

Swift Solo rudder cassette build instructions

Cassette rudders from phils foils for various farrier tris


Hoot dinghy rudder cassette


Swift solo rudder cassette

 

The GBE 29' cat uses lifting rudder blades - seem to work OK but doubt they will "lift" of encountering an object as they are designed to break the bottom third off if significant impact...

 

Thanks everyone so far. I'm throwing a few ideas around regarding this.

It would be nice to have retractable rudderblades that can be replaced... but I don't like the idea of it breaking off on impact.

The kickup could have it's own challanges if you try to steer in shallows...

Could a conbination of the two be done ?

 

Image is from phils foils




Image from f-boat website

 

Gunboat 48 rudder.

 

Gunboat 48 rudder. Possible shapes?

 

Have they proven that shape works well Perry?

 

MB,

The whales would have given them up if they didn't! The indentations on the leading edge improve the stall characteristics.

Perry