If you're planning to explore the deep underwater zones in Fisch, you'll need good oxygen gear. The Advanced Oxygen Tank is the best choice for staying submerged during long dives, especially at the Northern Summit and beyond.

This tank holds way more air than the basic versions, letting you reach distant caves and hunt for rare fish without constantly resurfacing.

What Is the Advanced Oxygen Tank?

The Advanced Oxygen Tank is an upgrade to the Intermediate Oxygen Tank. It's gear you wear to breathe underwater. The main benefit: it gives you much more oxygen capacity, so you can explore further and stay down longer.

The tank holds different amounts of air depending on where you dive. At the Frigid Cavern area near Glacial Grotto, it lasts about 6 minutes. At the Overgrowth Caves, it gives you roughly 45 minutes of breathing time — a huge difference.

💡 Tip — Check your oxygen meter before diving. If it's low, surface and wait for the tank to refill, or head back to camp to buy a fresh one.

How to Buy the Advanced Oxygen Tank

Getting this tank is straightforward: you need 25,000 Cash and you need to reach the Glacial Grotto.

  1. Earn or gather 25,000 Cash. You get Cash by catching and selling fish, or by completing tasks in the game.
  2. Travel to Northern Summit and make your way to the Glacial Grotto (also called Camp 5).
  3. Look for the campfire in the area. Near it you'll find Hiker #10.
  4. Talk to Hiker #10 and select the option to buy the Advanced Oxygen Tank.
  5. Confirm the purchase. You'll spend 25,000 Cash and receive the tank.

Once you own it, the tank goes into your inventory and you can equip it anytime you're about to dive underwater.

Where to Find It

The Advanced Oxygen Tank is sold only at the Glacial Grotto in Northern Summit. This is one of the deeper areas of the game, so you'll need to have progressed far enough to reach it safely.

The tank is located right near the campfire at Camp 5, next to Hiker #10 (who sells it) and the Advanced Glider. You can't miss it once you're in the zone.

💡 Tip — The Advanced Glider is also sold by Hiker #10. Consider buying both if you're planning a long exploration session in Northern Summit.

Why You Need It

If you're diving at Northern Summit or exploring caves deep underwater, a basic oxygen tank won't cut it. You'll run out of air before you reach the good fishing spots.

The Advanced Oxygen Tank gives you the breathing time you need to explore thoroughly, find rare fish, and make it back to shore without panicking. It's especially valuable at Overgrowth Caves, where the extended air supply opens up whole new areas.

💡 Tip — Bring extra cash when diving. If your current tank runs low, you can sometimes surface near a shop and buy a fresh one without losing your progress on fish you've caught.