Mark has been sailing his Matt Leyden designed “Paradox” Microyacht for some time and found it a bit “sticky” in lighter wind. He asked us if we could increase the sail area. He said that the reefing is so effective that the boat can take a larger sail.
The new sail he requested us to draw up is about 15% larger than the original, but importantly has a higher peaked yard which improves windward performance. It is tweaked to keep the sail centre exactly where it was with the original sail.
He likes the better light wind performance and says the boat feels more like a dinghy rather than being stuck in the water in light wind like a yacht.
No changes to the spars so this sail will retrofit to most existing Paradoxes.
I had a small concern that the extra fullness of the sail might cause a deep out of control ‘belly” just above the boom when the sail was rolled to reef. I suggested that if this occured put a piece of foam from a yoga mat cut into a lens shape in the first roll as the sail is reefed. During lawn sailing Mark thought it seemed OK without it.
By “lens” I mean thin ends and a fatter middle made to the same length as the foot of the sail. The fatter middle bit means that more sail is rolled up in the middle of the boom rather than the ends. Nothing original in this – the same trick is used to stop the middle part of roller reefing genoas from losing their shape when they are partly rolled to reduce the sail area.
For those unfamiliar with the Paradox they are a boat with a good reputation for getting to places where a normal dinghy won’t go – particularly for a boat of their length. They don’t have a centreboard or leeboard, but like a traditional yacht use the depth of the main hull when the boat is loaded along with a sail that is set back in the boat over the rudder. The rudder is the most effective foil on the boat. There is a lot of chat about the effectiveness of the “chine runners” but the designer himself points out that they only work in conjunction with a hull that is deep in the water.
It might seem weird, but Mark has been sailing since he was six with many years of racing in hot classes like the J24 and Etchells.
On traditional boats … the deep hull also does most of the work of a modern keel and the keel in this case becomes like a “stub” to increase the hull depth and provide a bit of a “fence” to increase the depth of the hull. A naval architect would say it increases the “span”. Some might look at the extra area at the back end, but most lift in a hull of this type is from the forebody.
Matt’s genius in this design was to apply the same principles to a boxy, relatively light hull with much less draft than traditional boats uising the same principle.
The Falmouth Quay Punt below was effectively a “Lighter” to bring goods from large square riggers offshore and bring the goods to shore (and vice versa) so actually have quite a boxy mid section as well.
But the principle is that hull depth is key. Without that the Layden Chine Runners and the stub keel on the Quay Punt will not be effective at all.
