Subject: [harryproa] Re: Pro vs bi-rig cat?
From: Mike Crawford
Date: 4/3/2008, 2:49 PM


  You're right about what you can do with a cat, and that if you reinforce a bridgedeck cabin enough, you can also get the benefit of a freestanding rig. 

  In many ways, there are no inherent advantages of a proa.  It all really depends upon what you want to do with your time on the water.

  If you want to carry as much weight as possible for the least investment, a cat might be a good solution.  If that is the main criterion, I'd suggest looking at a Wharram Tiki 38 or 46 ( ).  It will be difficult to find a tougher, safer boat that can be build for less money.   They are also beautiful, provided one likes their lines.  Of course, I'm a big Wharram fan, so I am biased.

  Where a proa start to shine is sailing quickly and safely.  The big two reasons to get a proa for me are:

  a)  Performance per dollar, as well as performance per unit of weight.

       Take the Visionarry Sport ( ).  Here's a boat with a galley, two queen bunks, a stand-up head and shower, a third single bunk/closet, and storage in a long row of cabinets and in the lee hull.  Okay, none of this is revolutionary.  But when empty it has a Bruce number higher than an empty Formula 40 cat, a boat with no accommodations.  That's amazing.  That it does so with only $50,000 of materials (give or take, not including cruising fit-out such as ovens, electronics, etc.) is even more impressive.

       To get that level of accommodation in a catamaran or trimaran with the same level of performance would be quite expensive, and would require a much larger boat in terms of total material (and therefore higher cost).

  b)  Ability to handle various winds with less stress and effort.

       The first trick in handling difficult weather is to reef early and often, and that applies to proas as well as to cats and tris.  A proa has a few unique advantages, though.

       Shunting, rather than coming about or gybing, can be done gracefully in any wind.  In light winds, you can tack a proa out of a crowded harbor in winds that would never allow a catamaran to come about.  In heavy winds, shunting can be less stressful than coming about, and is definitely far safer than gybing. 

       You can also stop at any time, and reverse direction if needed, in order to pick up a man overboard.  Or, if the weather is really bad, you can turn around with a controlled shunt instead of trying to plan a 270 degree turn in between steep wave faces.


  The Harryproas have other advantages that come from Rob's work with unstayed masts.  Having the accommodations completely free of mast supports and daggerboard trunks is quite nice. 

  Not having to carry tens of thousands of dollars of rigging and parts is equally beneficial, especially since 50 extra parts (wires, swages, chainplates, turnbuckles etc.) means 50 extra points of risk for a dismasting failure.  It's really difficult to determine if there's crevice corrosion or stress fractures in stainless wire and fittings, and if you intend to sail a boat for long periods of time, there's a lot to be said about doing away with the rigging.

  The flexible masts are also great at reducing stress on the boat, as well as avoiding capsizing in big gusts.

  With kick-up rudders and no daggerboard trunks to fail, the Harryproas are also great if you happen to hit a sand bar or whale.  Underwater collisions that would sink other boats would simply require retrieval of the rudder and re-fastening its case.

  There's also the chance, especially with a schooner rig, that the hollow carbon masts would have enough flotation to keep the boat from capsizing past 90 degrees in a knockdown, and then allow the boat to be righted.  I'm not aware of any other multihull with queen-sized beds that can even dream of doing this.

  A schooner rig would also be pretty easy to sail even if both rudders somehow failed.  The twin sails, combined with the ability to shunt, would allow maneuvering in most winds without any steering device at all.  Sailing a catamaran without a steering device can be near impossible in low winds (can't come about without a rudder), and pretty scary in high winds.


  This is not to say that the proa is better for living aboard.  It's just that the proa has unique advantages in the areas just mentioned.

  In the end, many sailors will look at a proa and decide that it's awfully small for its length.  What?  You only get that for 15 meters?  Why, a 15 meter catamaran would have huge amounts of space, and could carry tons of cargo!  True. 

  But that's also the point: the proa can provide a long waterline length for a given investment of money and materials, and therefore eke out more performance per dollar and hour spent building (assuming you don't overload it).

       - Mike

gardner.pomper wrote:

After following the discussions on the advantage of proas, and playing
around with a layout for a liveaboard version, along with very limited
info about the upcoming charter version of the harryproa, I realized
that I seem to be missing some basic points.

The proa has an advantage because all the stresses are concentrated in
a small portion of one hull. That seems to be mostly due to the
ballestron (sp?) rig.

Weight and cost can be kept down by keeping accomadations out of the
hulls and putting them on a bigger bridgedeck. That would apply to
cats too.

So, I am wondering, if you design a bi-rig cat with a freestanding
ballestron rig in each hull and just put everything up on the
bridgedeck, wouldnt that work pretty much as well as the proa concept?
It would seem that the weight would be about the same.

Things would be different; you would have 2 identical hulls to build,
somewhere near the average of the ww and lw hull sizes. That should be
easier. You only have to sail in one direction, which would make the
rudder and wheel designs easier. You could mount inboard diesel
engines, which would be handy for liveaboard crusing, so you can
travel when there is no wind. You do need 2 masts, and they would have
to have shorter booms, so they don't run into each other.

Can someone give me a clearer picture of the inherent advantages of a
proa? (not compared to cruising fat cats, but for a liveaboard couple,
wanting a small level of comfort)


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