Lets start with a disclaimer, this is an opinion page, and it is just that, my opinion, it may be right, it may be wrong, it is just what I think, no more, no less

Why do I think tacking outriggers have potential? Good question. Here is an answer, simplicity and a lot of boat for the dollar.

Lets take some examples, if we look at Tim Anderson's modified Canadian canoe, as seen HERE, we can see how a very capable craft can be had for a modest outlay in money and in effort. Moving to greater weights we can see the simple Kejak tacking outrigger, as seen HERE. Looking at this craft we can see the simplicity of the craft, how easy it is to build, and yet it still has reasonable performance. Compared to a similar sized ballasted craft, we have much reduced weight, a shoal draught capability, unsinkability and good initial stability. The boxy simple shape of a craft like this means that highly skilled traditional boat building techniques are not essential

Another good example of how a capable craft can be had from modest means is Dave Pont and his Korari tacking outrigger. Basically a double canoe with an outrigger added. When combined it creates a craft that is capable of high speeds, is very light weight and yet can handle fair sized waves. If the canoe did not have the outrigger it would be very tender, have to carry much less sail area, and be limited in where it could go.

Terminology
Tacking outrigger, tacking proa, tacking outrigger sailing canoe. To me these all mean the same thing. I use the term tacking outrigger because that was what I read somewhere. The best term is whichever you like the most.

Tacking Outriggers versus proas
I think that proas are probably superior sea boats when compared with tacking outriggers. However tacking outriggers have the advantage of being simpler. Conventional center-boards, sail rigs, rudders and their fittings can be just slotted in. A proa requires the crab claw sail to work well, which requires a higher degree of skill to use than a tacking rig. The proa requires a steering oar to use, which is OK, but is going to be tiring on long trips, alternatively very complicated dual rudder set-ups are required.

Tacking outriggers versus trimarans
When comparing the two, it is obvious that trimarans are going to be faster craft. The downside is that they are likely to be large and heavy compared with a tacking outrigger. If you take for example the Norman Cross 18ft trimaran you can see how the 2 large outriggers add a lot of bulk, weight and complication to the design. Yes the craft will be faster than a boat with a single outrigger, but the all up weight is now so high that manhandling it single handed up a beach becomes a most difficult exercise.

Tacking Outriggers versus catamarans
The catamaran is fast, seaworthy, fairly light, simple and effective boat. The downside is that they can tip if pushed too hard, and there is usually no protection for the crew from the elements, nor is there usually cargo carrying capacity. An exception to this rule would be Ray Aldridge and his Slider catamaran. With Ray's cat we can see that we have two large heavy hulls, the end result seems very good, I personally would prefer one hull optimised for carrying cargo and crew, and the other as an outrigger

Why did the Polynesians not make more use of tacking outriggers
The Samoans did have tacking outrigger sailing canoes, as can be seen here. Perhaps why they did not make more use of them is that they were limited in their outrigger material. The outrigger was limited to a solid log. The Polynesians did not have the ability to make a hollow outrigger and also to keep the water out. With their superb proas they often had bail the main hull (vaka) to remove water that got in. The outrigger was too small and too exposed to permit bailing of this hull, so they were limited to solid outriggers. Now these will work well with the outrigger to windward, but when it is on the lee, the small reserve volume will limit the sailing force that can be applied.

Tacking Outriggers versus Harry Proas
Again this is just my opinion, no more, no less. I think the plus is the minimal structure needed to achieve the same results with a tacking outrigger compared with a Harry-Proa. If we look at how simple and light the modified Canadian canoe that Tim Anderson used on his Seattle to Alaska trip, and compare that to the Harry Proa Elementary. It can be seen that the modified canoe has much less structure, can get away with very lightly crossbeams and is overall a much simpler and modest craft compared to the Harry-Proa craft, and yet on the upside it has the carrying capacity to take Tim from Seattle to Alaska.  The cost of the modified canoe could be in the order of a thousand dollars, whereas the Harry-Proa craft is going to be many multiples of this. This being said it must be noted that the Harry-Proa craft are very commercially successful

How modern technology assists the tacking outrigger
Two pieces of modern technology assist in making the tacking outrigger of today very viable. One is the plywood and epoxy resin technology that permits the construction of strong, lightweight, watertight and very buoyant outriggers. This permits the outrigger to be used on the lee side with ample reserve buoyancy. The other modern technology is plastic tubing and water pumps. The ideal set-up would have the outrigger built very light, but with an inbuilt water tank. When the outrigger is on the windward side, this tank could be filled with water to increase righting moment, When the craft is to have the outrigger to lee for an extended period the water tank can be emptied so as to lighten the craft overall and make it that bit faster

The tacking outrigger niche
I see a small niche in the market that the tacking outrigger is an ideal fit. I call this the adventure market. A craft that is capable enough for the sea, stable enough to get onto a beach in moderate surf, light enough to be brought up a beach single handed, has protection from the elements for the crew, and has cargo capacity for a trip of a few days. The trouble is that this boat seems to be sought out by very, very few people. However trying to change people is a hard thing, the best that can be done is to make them aware of the option and leave it at that.

Ideal size of an outrigger
I have heard of a few outrigger canoes being built with very light outriggers and then tipping over. I have read of a Ulua tipping over, and more recently Leon Close and his Kalang outrigger tipping in surf. In my opinion the outrigger should be a more buoyant and have more weight than some advocated. My overbuilt outrigger probably weighs more than 40kg and has a volume of 220L. Now this I feel is too much as moving the outrigger around becomes very hard work. I made mistakes in construction and did not build lightly. I feel a better outrigger for a tacking outrigger craft of about 18ft would be in the region of 20 - 25kg weight an a volume of 150L. It should be noted that the VirusPlus tacking outrigger comes with lead weights in the outrigger to increase its righting moment!

On Safety Amas
I think these are good. In my opinion they provide a lot of reassurance for minimal downside. The Hawaiian outrigger sailing canoes that do a lot of ocean sailing use safety amas extensively. I recall that the 40ft proa Equilibre tipped over in the Caribbean, it did not have a safety ama. More recently a 25ft proa by the Guilliard family (no safety ama) which sailing in the French Mediterranean, tipped over and some expensive equipment was lost. It should be noted that all four of Russ Brown's proas have safety amas. In my opinion it is very prudent to have one fitted, a lot of upside, very modest downside. 

Talk is cheap. Actions speak larger than words. I am most aware of these two pertanent issues. I have done a little, I have built one real boat, put ideas up on the web for others to possibly benefit from. Things are changing and in 2011 I intend to have another craft for the water. It may be that it will end up being a modest little rowboat. It may possibly have the ability to carry a little lugsail for reaching and downwind work.

I keep coming back to the replacement boat idea, and can only see the most modest of improvement to be made, perhaps a higher and narrower stern. Some method of removing side bench planking to allow for paddle strokes, and then place it back in again when desired. I saw a nice proa for sale in Queensland for a good price recently, nice size too at 33ft. I was tempted to buy it, but am 12 months away from being in a positiion to do so in any logical way

I think more tacking outriggers will be built, and people will be happy with them, My guess is that the better ones are possibly the smaller cheaper ones. The peace of mind when going into the ocean in a small boat that cannot sink, is not something that is going to go out of fashion anytime soon.