Picture Of My New Vertical Rudder


Well-Known Member
Took my old mahogany daggerboard that I was no longer using and re-purposed it as a vertical rudder. Photo below.

Features include...

- The trailing edge of the old daggerboard is now the leading edge of the new rudder.
- Fully glassed the rudder head. So no chance of cracks in the wood appearing... unlike other Sunfish rudders I've had.
- Rudder cheeks, tiller straps and spring bolt holes all consist of large holes drilled in the mahogany, filled with resin mixed with West Systems 404 high density adhesive filler, then re-drilled to bolt size. No more holes getting larger from wood wear.
- Bottom tip of the rudder and several inches of the leading edge and trailing edge just above the tip glassed over to prevent dings when dragging over rocks and other stuff in shallow water.
- Spring bolt positioned further aft to create more tension to keep the rudder in the down position.
- New tiller is a hockey stick shaft.

Haven't sailed with it yet but will report back when I do.


- Andy

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Interesting. Where I sail (I am the only sunfish) the laser sailors are always telling me that my rudder isn't down properly. A rudder like this would at least stop that happening.
Looks a lot longer too. If you use the new glass board, it would be interesting to sail with another Sunfish along side to compare.
Looks a lot longer too.
When deciding on a rudder length for this new vertical one, I used my Laser rudder as a benchmark. After I made my Laser rudder vertical, the tip of the rudder was 21 inches from the bottom of the transom. Using that as a guide, I made the tip of the vertical rudder on the Sunfish also 21 inches from the bottom of the transom.

However, when the Laser rudder was in its original, slightly swept back position, the bottom of the rudder was 18.5 inches from the bottom of the transom. So I may cut a bit more off the bottom of my new vertical rudder for the Sunfish.

If you use the new glass board, it would be interesting to sail with another Sunfish along side to compare.
Clearly, I've got a lot more surface area (drag) in the water than the stock Sunfish rudder. So, if I was sailing side by side to an identical Sunfish, with both boats flat and both rudders on the centerline at zero angle of attack, the other sailor may be faster.

However, if the other Sunfish starts to have to correct for weather helm by turning their rudder in stronger wind and I'm not, then the tables are turned in the rudder drag department.

That being said, I made this vertical rudder mainly so friends could sail the boat with a higher boom (center of effort further back) but not have to deal with an increased weather helm. For example, my wife and I took the Sunfish across Tomales Bay to a beach to hang out for the day. In preparation for this, I raised the boom some so she wouldn't have to duck so low when we tacked (she was forward of me in the cockpit).

As soon as we hit the water and started to point, I noticed more weather helm on my old rudder than when the boom was lower.


- Andy
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I had this sharp 90 degree angle on my 14 sloop and I found any time you relaxed your grip on the tiller, it went full lock to one side or the other. I changed that rudder to around 12*degrees of trail and now I can let go for a second or two and it has a very slow weather helm. Just a little trail in the geometry made a difference. I did remove about 20% of the trail from my Sunfish by re-cutting the front angle and plugging and raising tiller mounting hole 3/4 inch. It reduced the pressure on the tiller a lot and it does sail better. When I cut a new rudder, I'll try roughly 50% of the trailing angle of a stock one.