People went to Australia and many remote islands in the oceans thousands of years ago. Probably had as good boats as the guys in the Mediterranean.
But off hand I do not remember when the Polynesian started their migrations, was it 3,000 years ago ? Their boats and navigation were quite remarkable back then.
Anyway, makes sense that the Mediterranean area had good boat tech at such an early time. It is a kind of "closed" area and you throw a boat in it, it will run into some land after a rather brief time. So people with faster and reliable water transport would do better than people without.
I would not be surprised if they find some good boat tech much much earlier.
https://www.researchgate.net/figure/Coastlines-of-Australia-...
This would be the collision of actual real world relevant experience and ALotOfReading.
We know very little about these people and their technology, but it's worth pointing out that this is the first definitively established oceanic crossing in human history. In fact, it's one of the few crossings we know about until many thousands of years later in the Holocene.
This is something that comes up regularly in these sorts of studies. There's a lot of ideas, skills, and technologies that look "easy" to us because we benefit from standing on the shoulders of giants, but are extremely difficult when you don't have that hindsight. It's entirely possible that this was a monumental feat to these people. It also might not have been, so I avoided describing it either way.
Anyway boats were re-invented many times in pre-history.
https://en.wikipedia.org/wiki/Lykov_family is a good example that n=6 is way too few (even if the cultural knowledge is still there, the material goods, eg seed stock, hit absorbing barriers).
Do we have any reasonable (astrophysics-level) estimates of the population sizes necessary or sufficient to support some transect of various cultural and technological practices?
Migration to Australia was in fact extraordinary, which we know because in an another place with significant seafaring culture, it took 50ka longer to do a shorter trip.
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 https://en.wikipedia.org/wiki/Channels_of_the_Hawaiian_Islan... in the Hawai'ian islands is where one starts to sail for Tahiti. It was far enough away (4'000+km; ~20 days sail?) to Tahiti that by the time the polynesians made it out there the original Hawai'ian colonists had lost the linguistic distinction between /t/ and /k/ in "kahiki" — but they still knew how to get back.
FWIW Taiwan seems to have been the cradle of Pacific seafaring culture.