Madagascan outriggers

I am afraid I don't. I can speculate though - parts of the coast would have been used by Arabian traders on their way South. The sailing rigs I have posted correlate closely to those on the African East coast where the Arabs traded and this design seems to have moved South. (So for example to Mozambique where lateen rigs are the order of the day it seems). Presumably this design migrated to West Madagascar. I haven't seen square rigged boats (but haven't looked) - but if India and Sri Lanka were to trade that far South, and there is evidence of indian trading centuries ago with Africa, they would landed on the East side of Madagascar. So perhaps each side was influenced by different cultures in their sailing rigs depending where that culture landed. To some extent they would also be sailing home against different prevailing wind types depending which side of the long island they were on, and this might impact on the rig if you are bringing fish back and don't want to paddle. A tack might be required on the West side so one can sail into the wind, but on the East side you might generally be running before the wind on the way back. But I am just hypothesising....