28 February, 2013

Rio de la Plata conditions.

Before I began to talk about the new design is good to explain how are the water condition where I living. "Rio de la Plata" means a river of silver and this name is related to the expediotions of conquistadores from Spain. This is the bigger estuary around the world and the conditions can be worst than in the ocean, a couple of weeks ago in summer we get waves of five feet with a period of five seconds and strong winds. "Pampero" from the west or "sudestada" from southeast normally comes with no warning, are too strong, and normally produces big changes in water deepness.
Talking about the last- we got from five to fiveteen meters of water, so is very normal to sail in breaking waves. Most of the fishermen use a dory hull, in cedar but sometimes they drown in the surf near the shore.

27 February, 2013


NA-Y boat results very seaworthy. I can't post a pic about but I seen this boat floating over a two meters breacking wave in the surf a day when the swell was very strong.  The boat was very light and the water flows down the chines. Once I sculled her in open waters when the ferryes still at dock.
You can believe or not, is up to you.
Yulohing it is a bit slow but not very hard, I remember that day I mentioned before, the waves was something like six feet from the stern cause the wind, and also six feet from starboard cause the tidal. The yuloh I did based upon similar proportions of Slieve Mc.Galliard suggest works fine in the waves- also over the wake of the ferrys as I a bit scared tested several days ago- .
The only problem with the NA-Y was crossed winds. The next hull will need something like leeboards or chine runners. I think Yrvind's development is special for this kind of boat- but will need modifications to use it in assist the wave propulsion (something similar to to chine runners is mentioned in Gardner dory's book).
The wide stern from the original planning hull was a good choice. In a multichine boat light as this the water will flow very good to the exit with no need of a narrower buttock when doesn't have the weight of the engine hanged in the stern.
After I discarded the engine I did the yuloh from scrap. The main arm- paddle and longer loom- comes from an old whales boat oar in red hard wood -"platanillo" in spanish- with the addition of a smaller arm at twenty degrees or so. Works well as I tell above - but better can be a development of a vertical blade as I did in my first draws (mi first attempt was a vertical blade and was better- two to three years before but was stonlen) and this also can be used in automatic position when sailing in good waves.

I tested an small sail but is not necessary except in conditions of wind with not waves- something difficult to found at sea. In my next hull I will consider all the boat as a sail to take advantage of the wind. This sail is the orange thing you can see over the deck - folding mast-.

26 February, 2013


First of all, I'm not an expert, but I got enough knowledge to say some people around still exagerating about the difficult to do a floating thing. With patience, some skills and tools is possible to do a boat. If you got the plans a some assesment is not impossible.


This is the better history of marine wave propulsion I found in the web. By clicking in this link you will found a well registry of the background of this thecnology. Click here.

Burocracy can sink you.

Is hard to explain how I loose the boat and all the work done after three years- but this video can illustrate a bit. Anyway I'm almost ready to build an improved hull.