Since Subnautica is a paid title, the only way to safely and legally download specific versions is through official storefronts. Where to Download Subnautica
If you cannot afford Subnautica, the developers offer a free "Subnautica: Early Access" prototype on their official website (no longer supported, but legal) – search for "Subnautica v32386" instead. subnautica v71288 download
This version number corresponds to an older build of Subnautica (likely from 2017–2018, before the full release). The current stable version is much newer. Since Subnautica is a paid title, the only