Hi Taru and Alex,

I'm just finishing preparing our yacht to set off on an adventure similar to yours. We too had what I thought was excessive weather helm and wanted to tackle that as part of our pre-departure work.

Clearly all yachts are different but what I found on ours was that our mast had far too much aft rake; the forestay was about 12 cm too long (42ft yacht ~19m air draft). When we re-did the rigging I adjusted the forestay length to put the mast at about one degree of rake (We had about 3 degrees of rake before). The reduction in weatherhelm has been spectacular. She is now so balanced with just finger tip control needed below about 15 knots of wind when we need to think about putting in a reef to balance it all up again.

Maybe Alex has checked the mast rake already but if not it would be worth checking it whilst you are still afloat and level because mast rake is much easier and cheaper to adjust than the modifications to the rudder you have described.

I'll keep my fingers crossed you get an easy fix as you both deserve a lucky break after all of the amazing work you have done so far.

Fair winds

Reg

The design of the rudder being swept back I think would give quite a bit of helm. If the rudder was staight down and with no fixed leading edge you would have less helm and better control. Just a thought....based on all the keel rudder combos that I have seen. Duende should have a spde rudder. I'm sure that is a performance rudder. I saw Duende for sale on yacht world....and thought what a big honking rudder....the strain on the steering gear must great. As well as hard to drive for long period on watch. These are just my own thoughts. Does you main sail have UV damage to tear like that. Before you hit the pacific crossing replace it...Michele Steven's Sail Loft in Nova Scotia.

Boat is looking sharp

Scott From Nova SCotia

Hi Alex,
I'm sure you've never received unsolicited advice about your boat projects before (LOL). But anyway, here goes!

I built a 46' one off custom by a famous designer many years ago for a client, long skinny skeg like yours, but no rake to the rudder post. I put a dial indicator and hydraulic press on the skeg and rudder independently, and just as I suspected, the rudder was supporting the skeg rather than the other way around. A long skinny skeg like yours is almost impossible to build as stiff as a good SS or carbon rudder shaft. All it really accomplishes is to stall the flow over the rudder foil and make it impossible to build a properly balanced rudder.

Weather helm is basically a question of the balance between the sail center of effort and the center of lateral resistance, but an unbalanced barn door rudder can give the boat the same feel. And that rake certainly doesn't help.

Sailed on my friend's Garcia Passoa 46 that had been around Cape Horn and to the high arctic, and they swore by their aft daggerboards. Something I always thought I'd include if I got a chance to build my ultimate boat. If you have the trunks in place I wouldn't take them out.

Hope you get a chance to explore more of Colombia before heading out.

Cheers,
Richard

ps. If you haven't come across it yet you might want to check out John Harries "Attainable Adventure Cruising" site that I contribute to sometimes. A number of very experienced sailors enter into the discussions, and it has a readership nearly as large as the print sailing rags.

It is really nice and interesting to read about the boat, because I have no sailing experience at all. You teach me a lot!

Not wanting to teach Granny to suck eggs, but I'm a Naval Architect in my day job. The advice above is sound, you must resolve the poor yaw stability before you try to refine the rudder, as without good helm balance, you will always have a directionally unstable boat and high rudder loads.

The form is deep and narrow forward, rising rapidly aft, a shape that is inherently directionally unstable since the deep fine forefoot, when yawed, will generate high complimentary yaw forces. Such a shape is common when matched with a long keel, but with a fin keel it is problematic.

This combination was common in the early 70's as designers moved to fin keels (high lift, low drag) but hadn't fully understood the problems of combining this with the fine, low wavemaking forms that were previously used with the long keels.

First job is to quantify the issue. Go sailing and deliberately induce yaw instability. Try to assess whether this is just helm balance (characterised by high initial rudder load, diminishing as the boat yaws), or also includes amplification due to the hull form (small changes in yaw causes sudden rapid increases). My guess is you have both.

For helm balance, you have several option:

Firstly, in what state are the sails? Old sails tend to bag and the centre of effort moves aft, so if this is the case you should identify this before modifying the boat unnecessarily.

Since you are making a new mast step, you may have an opportunity to move the mast base forward a little, commensurate with the internal structure. This, combined with modifying the rake if possible, could improve helm, but personally I'm not a fan of positive (forward at the top) rake on a mast on aesthetic grounds.

You could also add a bowsprit, though I would also object on aesthetic grounds.

The other options are underwater:

Firstly, you could reinstate the daggerboards. Using aft daggerboards will provide a lot of directional stability, but it is a poor substitute for good basic balance. The daggerboards close to the rudder prevent good steerage when you need it, and need to be down when you need them. However, with your hull/keel combination, they may provide a compromise to improve control without negating too much the performance, and they are removable when not required. If your rudder was a keeper this would be the simplest fix (if the boards are still there)

However, if it was my boat, I would be looking to change that rudder to a semi-balanced spade with the stock further aft, mounted off a half depth skeg that starts about halfway between the existing keel and skeg, runs aft parallel to the waterline, then down into the spade profile. The skeg would assist in reducing the form issues, the rudder loads, and go some way to improving balance, though some movement of the CoE will likely still be required.

This mod is basically what was done in the late 70's/early 80's to make the boats like yours more directionally stable, before the designs moved to more rounded forward sections to reduce the effect, and is a common configuration on HR's, Swans, etc. It wouldn't be a major undertaking for someone of Alex's capabilities.

That sounds like good advise Guy....I would start with putting the dagger boards back in service. They were part of the origanl design of the boat and there for a reason.

Scott

Thanks a lot guys. will have a look at your suggestions as soon as it's time for the yard.

I know zero about boats, so I can't offer any helpful advice, but I just wanted to say she's such a beauty!!!!