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 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 10 meters swum. This applies even if you're swimming up using or down using. The energy generation is higher than the Seaglide's energy consumption, thus allowing unlimited use.

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.

The Swim Charge Fins require a swim speed of above 2.0 m/s to work. If you are carrying too many tanks (including paperdoll-equipped), you may become too slowed down to charge anything. Equipping the Reinforced Dive Suit also slows down swim speed. Using the Seaglide will still result in charging due to its speed being unaffected by tanks. See the article on Swimming Speed for more information.

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 1.90 m/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 inside an Alien Containment, despite a much higher swim speed while inside one.

Trivia
When something is charging, the fins whirr noticeably.