FOILS
I share the viewpoint that there may not be a problem with the
newest version of the beam-mounted kick-up foils, *if* the boat
design works with them.
BD has special draft requirements, as does Gardiner's plan to sail
in the Chesepeake, and both could be nonoptimal with low-draft
beam-mounted rudders. Without enough foil in the water, it's easy
to go from laminar to non-laminar flow, and then the foils become a
lot less effective. But such is the challenge with a 48' boat
designed to sail in 3' water, and yet somehow be expected to hit 20
knots (by observers, not by the owner).
But what if we didn't have to go with the original Vis design in
the original sailing waters?
With another 1' to 2' in rudder draft (4' to 5' total), a schooner
rig that allows different sail balance, and Rick's hard-chined
flat-bottomed leeward hull form, leeway, tracking, and steering
should become the same non-issues that Rob had with Elementarry.
Particularly if I go with wingsails that create more drive and less
force to leeward. This might even work at 3' draft with the rudders
partially raised, but that remains to be seen.
[many, many thanks,at this point, to go Rob, Mark, Bain, Nol,
Arttu, and Johnny for all the real-world experience to date]
There's no denying that foils in drums, exiting the hull bottom,
would be more efficient. But I just can't imagine spending the
money it will take to build a 48' boat and then going with foils
that don't kick up.
In fact, I don't even want to spend the money on a used Corsair
for that reason. I know of a boatyard that has repaired the same
boat F32 three times due to encounters with rocks. You could say
that's due to bad choices, but sometimes groundings happen due to
events outside of the boat owner's control.
On a more personal note, I've had a friend run my own catamaran's
central daggerboard into rocks at 2 knots, and that just required a
few hundred dollars of repairs. If it had been at ten knots, I'd
have needed a new centerboard, centerboard bracket, and cockpit
deck. And if it had been in a trimaran instead of a cat, we might
have filled the main cabin with water. And if it had been at sea...
Most folks will put up with well-established risks, such as
daggerboards in trunks, multihulls that can't be righted if they
capsize, or complex masts with 50+ points of failure in terms of
standing rigging and connections. But if we're going to go
non-standard with a proa in the first place, why not go all-in and
eliminate all of the risks and shortcomings we can?
If I were to get a trimaran, it would be a Dragonfly. Period.
Because their centerboards and rudders will both kick up if run
aground, turning a high-speed grounding from a potential sinking
experience into merely an inconvenience. There's just no way to put
a price on that, particularly if you're out of sight of land.
But since the Dragonflys' diamond-stayed rotating masts have many
dozens of points of failure, and they don't even stand a chance of
righting after a capssize, a schooner Harryproa with sealed unstayed
masts currently occupies the top slot in my short list.
In any case, when the time comes, I'm going to risk the beam
mounted rudders; risk in the sense that I could end up replacing
them with a different system.
Just as important, rudders on the beam would permit simple tiller
extensions all the way to the cockpit, which is something I'd
definitely like to try. It's a simple system that wouldn't care one
way or the other if the boat were folded or unfolded, won't stretch
out of shape, and will be more fun than using a wheel. At least for
me -- I much prefer tillers.
- Mike