<<Would not larger sail and lighter weight favour the HP in light airs?>>

  That's a tough question.

  The long hull wouldn't help with very light winds, and I believe the tri will have a lower wetted surface area for a given displacement.

  But the proa doesn't have to carry around that extra ama, so it will have a lighter weight for a given righting moment, and that will reduce its surface area.  If the rigs are equal, the question isn't which boat has less wetted surface area for a given displacement, but which boat has less surface area needed for the righting moment that matches the sail.

  The two might be very close.

  I'd give the proa an edge for light air in terms of actual use for the following reasons:

    - In really light winds, particularly with a schooner rig, you can always shunt.  The tri will have a tough time coming about once the wind drops below a certain level.

    - The proa will be able to safely carry more sail area, so you can fly more sail, more of the time, without having to worry if the wind "gusts" from 4 knots to 8 knots.

    - Once the wind does pick up, the tri will eventually run the risk of tripping over its ama, while the long lw hull in the proa will be very seakindly.  Unless it's a tri with a huge ama to leeward, in which case we're not making the original comparison.


  The two would end up being really close in light winds, so I'm not sure you could declare one a winner to the extent that it would convince a trimaran fan to switch to a proa, or vice-versa.

  But if the proa can equal the tri in light winds, I'd have to go with it because of the performance and safety when the wind gets big.

        - Mike

 

Can not the HP carry a larger sail, compared to the tri, assuming similar margins of safety?
Is not the hp in this comparison assumed lighter than the tri?

Would not larger sail and lighter weight favour the HP in light airs?

Or is wetted surface the larger variable?

On March 2, 2019 10:35:57 PM UTC, "Rick Willoughby rickwill@bigpond.net.au [harryproa]" <harryproa@yahoogroups.com.au> wrote:
| The difference in wetted surface between proa and tri will not be 40%
| in light conditions but something less than that. There needs to be
| a reasonable immersed length of the ama to avoid wave making drag.
|
| Then the tri has the windage of the windward ama and its beams. That
| is not insignificant.
|
| The light air performance is likely to favour the tri but it would
| require detailed analysis to assess the difference.
|
|
| Rick