Embarking on the 'Investigate the Tadpole Pens' quest in Subnautica 2 requires a secret keycode, a critical item not found at the Tadpole Pens themselves, but hidden in a perilous, thermally active underwater region. Before setting out, players should prioritize enabling all landmark signals in the character menu to simplify navigation, and gather vital provisions such as sustenance, hydration, flares, a fully charged scanner, and an air bladder. The journey involves deep dives, making the air bladder's emergency oxygen a potentially life-saving asset, though only a basic air tank is necessary.
After receiving the 'tadpole pens' notification following the discovery of the Wander Blackbox and treating the Angel Comb, players can initiate their expedition. From the Lifepod, venture 690 meters eastward, without needing to descend until directly above the signal. The objective is an oxygen-emitting blue plant situated in a ravine opposite the Tadpole Pens entrance, providing a crucial oxygen refill point before entering the facility. Inside, pressing a red button reveals a locked door, prompting the search for the elusive keycode. While scanning the Pens is an option, the keycode is not among its discoverable items.
A subsequent alert from the Noetic Advisor will pinpoint the Zip Blackbox, which holds the necessary access key. Players can either return to their Lifepod's Noetic Advisor or proceed directly to the Blackbox's coordinates. For those at the Tadpole Pens, a 210-meter swim southwest, navigating through an alien structure and a tunnel leading to a fiery coral cavern, will reveal the Blackbox. Alternatively, starting from the Lifepod, a 350-meter southeast journey past Chap's Blackbox leads to a deep hole near an oxygen tunic, offering an entry point to the Hot Cave Basement before continuing north-northeast to the same fiery coral cavern. Regardless of the chosen path, the Zip Blackbox, resting on a large purple root at the cavern's bottom, grants the 'kurul level access key.' With the key in hand, returning to the Tadpole Pens and re-activating the red button will finally open the previously sealed doorway, completing the mission and revealing a breathable room with a Noetic Advisor.
Exploring the vast underwater world of Subnautica 2 demands both courage and careful planning. The journey through its depths, uncovering hidden secrets and overcoming challenges, truly enriches the experience, showcasing the importance of perseverance and discovery. May your aquatic adventures be filled with wonder and success.
