Swim Charge Fins (Subnautica)

The Swim Charge Fins are a piece of equipment and an item upgrade for the Fins that can be assembled using the Modification Station.

The Swim Charge Fins Blueprint can be acquired from the Data Box in the Underwater Islands Wreck.

They recharge the Energy of any tool the player holds in their hands as they are swimming. As a result, using the Swim Charge Fins reduces the overall need for batteries and power cells.

At the moment, it charges any tool held in the player's hand by 1% for every 10 meters swum. However, they do not produce enough energy to maintain the Seaglide's energy level constantly, though it still charges fast enough that it could be considered infinite.

When something is charging, the fins whirr noticeably, the whirr stops when the device is charged or nothing is equipped. The seaglide is partially powered by them, decreasing the loss of energy. Also, when you're swimming up using "space" or down using "c" it recharges the battery of the Seaglide.

The Swim Charge Fins must be placed in the feet slot of the paperdoll UI to take effect. When not worn they take up four spaces (2x2) in the inventory.

Swim Charge Fins only charge held devices when your swim speed is above 2.0 m/s. If there are too many tanks in your inventory (including paperdoll-equipped), you get slowed down too much to charge anything. Equipping the Reinforced Dive Suit also slows down swim speed. However, using the Seaglide will still result in charging due to its speed not being affected by tanks.

Swim speed with held device, Swim Charge Fins and without Reinforced Dive Suit = 4.75 m/s Numbers appear to be rounded to 2 decimal units. Swim speed has a lower limit of 1.90m/s.

For instance, wearing a Reinforced Dive Suit, with a Ultra High Capacity Tank in the paperdoll and one Standard O₂ tank in inventory would give a speed of:

4.75 - 0.95 - 0.61 - 0.8 = 2.39 m/s (Therefore Swim Charge Fins will work)

However, adding 2 more Plasteel Tanks to the inventory will bring the swim speed to below 2.0 m/s, thus preventing charging.

Swim Charge Fins do not work in Alien Containment, despite a much higher swim speed while inside one.