Swimming Fins and Seaglider - Extra speed is recommended for exploring deep waters.Park the Seatruck as deep as you can so you can return for Oxygen. The Seatruck - The Seatruck can be used as a temporary Oxygen-extender, though you will not be able to venture too deep into the Twisty Bridges without the Depth upgrade.It's found in the spawn biome of the Twisty Bridges and crafted with Wiring, Silicone, and Fiber Mesh. Rebreather - This piece of kit removes the Oxygen penalties for when you dive into deep waters.Take or two or three, if you have the resources. This tank will help you navigate for longer (and deeper) without worrying about Oxygen too much.
The High Capacity O2 tank - Crafted with Glass, Titanium, and Silver Ore.What you need before going Diamond hunting in the Deep Twisty Bridges: