How did humans cross these oceans and seas 50 thousand years ago? To land on the Indonesian islands, South Pacific islands, Australia, New Zealand... Did they

How did humans cross these oceans and seas 50 thousand years ago? To land on the Indonesian islands, South Pacific islands, Australia, New Zealand... Did they have massive ships that we'll never know about? Did they learn how to sail? Was it just small rafts and canoes? Oh, the sea-faring stories these people must have told.