The journey to decipher the Tadpole Pens in Subnautica 2 presents itself as the game's inaugural significant challenge. Your primary objective involves venturing into the scalding Hot Caves to retrieve a crucial entry key. Curiously, the game's AI companion, NOA, typically directs you to this location only after you've uncovered other vital data recorders.
Embarking on this expedition demands thorough preparation, as it surpasses the length of previous data retrieval missions. Ensure you're well-equipped with an ample supply of water, sustenance, fully charged power cells, and medical provisions. Additionally, considering a distraction flare could prove beneficial for unforeseen encounters. Following these recommendations will set you up for success in locating the Tadpole Pens and acquiring Zip's data recorder, which is essential for unlocking the facility's entrance.
Upon receiving the directive from NOA to investigate the Tadpole Pens, a beacon will appear approximately 675 meters east of your Lifepod, situated within the region's volcanic vents. To safely reach this destination, it's imperative to first acquire the Heat Resistance Module. This adaptation is obtained by neutralizing the hazardous Angel Comb formations located 200 meters northwest of your Lifepod, precisely at a bearing of 300 degrees on your compass.
Obtaining the Heat Resistance Module requires the deployment of the Sonic Resonator. This specialized instrument is used to eradicate the virulent flora within the area, thereby granting you access to the crucial thermal adaptation, similar to how you previously acquired the ability to process food. Furthermore, I highly recommend enhancing your oxygen capacity and constructing both a Tadpole mini-submersible and a Wavemaker, the latter enabling increased underwater travel speed.
Upon your arrival at the Tadpole Pens, you will encounter a sealed entrance, which necessitates a specific access code. You will learn that a former colonist, Zip, carried this code into the deeper sections of the Hot Caves. While NOA may eventually provide the coordinates for Zip's data recorder, it often involves a return trip to your base. Instead, you can follow these directions:
Once you have secured the data recorder and consequently the door code, you can return to the Tadpole Pens entrance. With the door now open, prepare to discover the unexpected secrets that lie within this mysterious facility.