Some thoughts.
I have had disappointing feedback from many people about the poor performance of proas they have built
Proas attract the attention of a group of people who see this vessel as a quick and easy boat to build and sail.
Quick, simple & cheap is an uncomfortable triad, poor quality is the result.
Considerable care must be taken to produce a high performance, reliable and safe sailing vessel. Care in design, construction, choice of materials will have a huge impact on the end result.
Many have built to their own design, often deep V ply construction or some other composite sheet material.
Building an efficient asymmetric hull is not a simple matter of making one side flat and the other curved.
No foil built in this way can be considered efficient.
I have never published plans of my proas and I never will. My conscience prevents me from doing so. The intellectual property belongs with the Micronesian people who designed the proa. The proa is a highly specialized and potentially dangerous sailing vessel. It takes years to learn the skill needed to sail one. I do not wish to place novices in danger of their lives.
The so called Kiribati dimple built into the lee side of the main hull is the secret to the success of a true asymmetric shunting proa. Without this feature your proa build will disappoint you with the absence of true windward lift.
Hull speed is another factor that contributes to hydrofoil efficiency. (Hull asymmetry) the faster the more lift. If you live in a region with consistently light winds this too will be a factor in poor lift performance.
Here in NZ we experience seasons with consistently high winds from 15-30 knots on a regular basis. Plenty of power to maximize the potential of an asymmetric hull.
Due to ill health I have retired from building and sailing proas, therefor my publication of more material will cease here.
Good luck to those who are prepared to keep an open and enquiring mind.
To the deniers and non believers, take a long walk on a short pier.
Best wishes from Harmen Hielkema.
