That the crossing of the longest stretch took place is a known fact.
The likelihood is that it was carried out by people that lived in an island archipelago chain and had, by the time of crossing, spent several generations building boats and very probably living a maritime life; huts and walkways on poles, more time on | over the water than land, diving for food, spending hours at night over shoals attracting octopus and other sealife with light.
In that context the crossing becomes a venture of following birds over the horizon for two days, some on a scale similar to what was already done to known points, once the first crossing occurs then the far shore becomes a place to stay when fishing for a generation or so and then becomes a location with a new village.
What does seem hard to imagine is humans arriving at the Wallace Line crossing never having had built a boat or a shallow water village before. I would assert that it's near certain that the required skills and technology were well in hand by the time they became essential to progress further to reach the Sahul.
The likelihood is that it was carried out by people that lived in an island archipelago chain and had, by the time of crossing, spent several generations building boats and very probably living a maritime life; huts and walkways on poles, more time on | over the water than land, diving for food, spending hours at night over shoals attracting octopus and other sealife with light.
In that context the crossing becomes a venture of following birds over the horizon for two days, some on a scale similar to what was already done to known points, once the first crossing occurs then the far shore becomes a place to stay when fishing for a generation or so and then becomes a location with a new village.
What does seem hard to imagine is humans arriving at the Wallace Line crossing never having had built a boat or a shallow water village before. I would assert that it's near certain that the required skills and technology were well in hand by the time they became essential to progress further to reach the Sahul.