The Arlington Springs individual was not the only person ever to reach Santarosae.

The island shows evidence of multiple early occupations and of resource use extending back to the same general terminal Pleistocene period.

What this tells us is that people were crossing to Santarosae with sufficient regularity that some of them died there and were buried there.

That regularity implies capability.

It implies not accident but intention.

It implies watercraft — some form of vessel adequate for open-water crossing, operated by people who understood the crossing and could make it survive.

What kind of watercraft?