dagger boards - why?

[pete]

I'll show my ignorance here, but i've never sailed a yacht with aft daggerboards i.e. hung on the transom as per drawings. What are they actually for?

I'm a little way off needing to make them, but currently just thinking of adding strengthening doublers to frame T for the transom-hung items - solar panel/ self steering etc - so trying to figure out what'll be mounted to it (potentially these daggerboard mounts) before i put it on the jig where this stuff will be harder to do.

I know that some shallow draught boats have the aft dagger boards for better tracking downwind due to their tiny rudders - e.g. Boreal adventure yachts (they look like a total afterthought on these boats) - and pretty much all the older designs by JF Andre etc.

And that they can also be used to balance the boat upwind to reduce weather helm (though this seems counter intuitive on a racing yacht, the sail balance should be optimised instead of an in-water appendage to take the place of some rudder angle).

So does a yacht the size of a mini 580 (with its already quite substantial rudder area) need them?

I guess the answer will be that we'll have to wait until Trekka is in the water until we can know for sure, but in the mean time maybe someone can educate me about what they are intended to do?!

[Admin]

Hi Having done a bit of sailing and knowing the difference in balancing the boat for nice sailing, and overloading the boat to power it up, hang on for the ride and go for speed...I will be fitting two dagger boards similar to design and construction that PIOTR did on his SETKA Atom... They may come in handy for racing. If I was just voyaging I maybe would not ...but then again i probably would ...Janusz rudder and balance of the boat will be good but small boats can be twitch so it may be an advantage ...good luck..

[jimschofield]

Thank you for your question Pete, I was wondering myself whether or not to fit the daggerboards.

Don's answer has kinda convinced me to fit them, also they look serious !!

Jim

[jimschofield]

Looking at the first picture above, of Atom's transom.

Can I assume this is the best and tried arrangement of all the furniture needed ?

Outboard to port, dagger boards, with rudder and self-steering gear in the center and solar panel to starboard. All these will need strengthening pieces inside so is it simpler to just double the transom thickness ?

Jim

[Admin]

Hi..all those aspects are up to you and there are many ways to skin a cat ...I am not worried about solar panels off the back...on the mini 6.50 they do as the main boom sweeps to the transom..on a Setka it is a smaller cockpit...my two aft panels are only 50 x 50 so I stick them on the Pushpit up 30cm so you can sit under then when Having friends over for drinks at the Marina...and I prefer the OB on stbd..ladder to port ...also I am having a solid rail across the stern as I know I will lean on that a lot and it is a little extra weight but easy to mount things on it.. I am also fitting an ECHOMAX XS Radar transponder that is quite big but easy to mount there...so a double transom thickness is NOT needed for me... good luck ! I posted the transom drawings of TREKKA on FB ..