Voyages of discovery? (spoilers for all RotE books)

[Rendezvous]

Im very new here so forgive me, I dont know how to do the 'box' thing.
Farseer said
"The Great Sail Fleet trades with and makes a transoceanic voyage west to Jamaillia every four years however there is no mention (that I know of) of anyone journeying TO the region from where the Great Sail Fleet hails. Is it possible that it is near their shores that the disappearing Others Island ships emerge? "
I always assumed that the Fools homeland was the place that the Great Sails Fleet came from, and although im not sure which book i read it in, I remember a mention of a white boy who arrived with one and went on to beg passage to the six duchies from the Satrap? The birthing place of the Great Sail Fleet of probably the last in the far south east mentioned on the map in Asvejal.