1 metre pond yacht

This is the starting point of an idea that developed into a much larger project.

Aerodynamics and hydrodynamics are very similar, apart from water is about 1000 times more dense than air. I had a couple of ideas concerning the reduction of drag in a sailing boat. In order to test them I could build a pond yacht, to 1 metre class rules, and run side by side comparisons. In that way I could avoid all the work, expense and endless, endless sanding of building a full size boat.

Until recently boat designers have taken huge amounts of resources optimising surface areas in contact with water. Aerodynamics have been largely ignored in the mistaken belief that they do not come into play until much higher speeds are in play. In this design anything that could induce drag was discarded, simplifying the design.

The hull is Eppler 347 profile, as are the wing, fin and bulb, and is 1 metre long. The cross section is circular.

I chose an Eppler aero profile #347 for it’s low drag characteristics while also retaining enough ‘’body’’ to make a viable hull. This was rotated 360 degrees and left complete. There is no rudder system shown, possibly the keel foil can be used to steer.

As the screenshots show the hull can lean up to 80 degrees from upright with no change in hydrodynamic shape, characteristics or handling, being able to sail full on at 80 degrees lean. The bow is intended to move the water aside without creating a large bow wave and also go through a wave. Traditional bows finely cut the water but also ride up over a wave creating a rhythmic rocking-horse motion.

Yacht at 0 degrees.
Yacht at 45 degrees.
Yacht at 80 degrees. The under-water, hydrodynamic, shape remains exactly the same as 0 degrees.

The sail/wing/mast is a symmetrical E347 divided into leading edge mid-section and tail-section and hinged. The controls run up through the midsection and apply torque at the base and half way up, to orient the sections into a power generating aero foil. There are no standing rigging or lines, therefore no drag.

The nose and tail section are rotated at 7 1/2 degrees
This is a later iteration showing the hinge section, with spacing for printed thin wall skins. The main central support is reinforced carbon fibre tubing

The gaps between each section can be sealed with Teflon strip, edge-on. This may stop, or reduce, pressure equalising from low to high.

The lower parallel section and upper, tapered, section of the wing.

The major flaw to this wing system is being unable to reduce the effective sail area without becoming overly complicated and heavy.