there was a discussion on the yahoo proa group a few months ago which itemized a few dozen ways to steer a proa:
http://groups.yahoo.com/group/proa_file/message/28989
ben
--- In harryproa@yahoogroups.com.au, "John" <jrwells2007@...> wrote:
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> There appears to be two different steering scenarios for a shunting multihull.
>
> When not moving, or very slowly moving, through the water the steering effect of a water foil is minimal or non-existent. Steering is effected by sail balance (i.e. schooner rig), very large rudders or a steering oar. This is not the total picture but approximates the problem.
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> Once there is reasonable speed through the water, steering can be very effectively carried out by water foils.
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> In the latter case an articulating lw hull might act as an inefficient but adequate water foil. A benefit of such a foil might be greatly reduced drag from other foils such as rudders and removal of the risk of rudder failure as speeds and forces increase.
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> I assume that someone has tried this. Can anyone comment on the results or point me to a source of data please.
>