I don't see why it wouldn't track straight. Planes flight level

Two linked counter rotating rudders down will always be better than one aft rudder down on a shunting craft. Look at my shunts in videos with linked vs unlinked . Its simpler faster and more effective over raising ,lowering ,and rotating, two boards that are unlinked.

My speed on current boat has been limited by sail area and design of sail Its A junk rig made of poly tarp and has sinse stretched out really bad top speed 12mph in about 15mph winds. I have a 120 sqft mylar full batten custom Hansen sail. But still need all the rigging.

Better yet would be to place a hobie 14 rig on my current boat and test.

That said I see no reason the foils can't be refined further for higher speeds still being connected to maintain effect.

Simple aero dynamics a slant/ or angle is less efficient than a striaght non angled leading edge. Same with a tappered chord vs a non taper one.

So why would you want to angle boards back for balance of boat sails center of effect and other factors. If balance is taken into consideration to begin with there is a buffer zone so to speak in lining up these force instead of angling boards aft which is inefficient!

Todd

--- In harryproa@yahoogroups.com.au, Rob Denney <harryproa@...> wrote:
>

> I don't believe a single unattended foil with the rotation axis at 50% of
> the chord will point straight ahead at 15 knots. Until I see one, and the
> physics that explains why, I cannot agree that it is a good thing to have on
> a boat.
>
> Linked rudders solve a lot of problems, but unless they work when one is
> raised, are no use. Rotating them aft is a solution, but is an extra layer
> of complexity. As the rudders have to turn for steering, turning them
> through 180 on a shunt is no big deal, unless they are mounted on the hull
> or utilise wheel steering, but even here, there are simpler methods.
>
> regards,
>
> Rob
>