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This article is about Swim Charge Fins as it appears in Subnautica. To see this subject as it appears in Below Zero, click here.
This article is about Swim Charge Fins. If this is not what you are looking for, see Fins (Disambiguation).

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 a data box.

They recharge the energy of any tool the player holds in their hands as they are swimming. Using the Swim Charge Fins thus reduces the overall need for batteries and power cells. It charges any tool held in the player's hand by 1% for every ten meters swum. This applies even if swimming up using Space or down using C. The energy generation is higher than the Seaglide's energy consumption, thus allowing unlimited use. Swim Charge Fins do not work inside an Alien Containment.

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

The Swim Charge Fins require a swim speed of above 2.0 m/s to work. If the player is carrying too many tanks (including paperdoll-equipped), the speed will be too slow to charge anything. Equipping the Reinforced Dive Suit also slows down swim speed. Using the Seaglide will result in slowly recharging the battery. See the article on Swimming Speed for more information.

Swim speed with a held device, Swim Charge Fins and without Reinforced Dive Suit = 4.75 m/s

Swim speed reduction in m/s (stacks with each other)
Reinforced Dive Suit Ultra High Capacity Tank Standard O Tank Lightweight High Capacity Tank
In inventory NIL -1.21 -0.81 -0.21
In paperdoll -0.95 -0.61 -0.4 -0.1

Numbers appear to be rounded to 2 decimal units. Swim speed has a lower limit of 1.90 m/s.

For instance, wearing a Reinforced Dive Suit, with an Ultra High Capacity Tank in the paperdoll and one Standard O 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 two more Plasteel Tanks to the inventory will bring the swim speed to below 2.0 m/s, thus preventing charging.


Fins.pngPolyaniline.pngWiring Kit.pngArrow-right (1).pngModification Station.pngArrow-right (1).pngSwim Charge Fins.png



  • When something is charging, the Swim Charge Fins whir softly.