Subnautica Wiki
Swim Charge Fins.png

The base Swimming Speed of the player without any fins or items in hand is around 5.7 meters per second, while fully submerged. Swim speed can be modified with fins crafted by the player using the Fabricator or Modification Station, or by equipping tanks or a Reinforced Dive Suit. Swim speed is also modified by holding tools or advanced hunger and thirst. Swimming at the surface increases swimming speed.

Currently, the fastest way of traveling is the Prawn Suit /Grappling arm combo.

Swim speed without holding a Seaglide is capped at an upper limit of 7.60 m/s and a lower limit of 1.90 m/s (Fully encumbered, holding a tool, no fins, underwater).

Swimming above the water is faster than below the water (base speed 7.4 m/s), and is also capped at 7.6 m/s

Equipping Oxygen Tanks and the Reinforced Dive Suit will slow swimming speed. Advanced states of hunger and thirst also reduce swimming speed, at a rate proportional to the severity of hunger or thirst.

Carrying an Ultra High Capacity Tank will decrease the speed by 1.0 m/s to 1.5 m/s (only the first 2 in the inventory will count towards decreasing speed). Strangely, no other type of air tank decreases speed when carried in the inventory.

Equipping any hand-held item (except the Seaglide) will reduce swim speed by 0.95 m/s.

When using the Seaglide, movement speed is a constant 11 m/s regardless of your equipment.

The Swim Charge Fins will only charge powered tools above a swim speed threshold of 2.0 m/s.

Effects on Swimming Speed (in meters per second)
Modifier Underwater (m/s) Surface (m/s) Remarks
Base Swim Speed 5.75 m/s 7.41 m/s
Swim Charge Fins (without tools) +0 +0 Needs swim speed of 2.0 or more for charging
Fins (without tools) +1.41 +0.19
Ultra Glide Fins (without tools) +1.88 +0.18
Holding a tool (without any fins) -0.95 -1.24
Advanced hunger ( less than 20%) -0.05 per 1% below 20% Max at 100% hunger is -4.00 m/s
Advanced thirst ( less than 20%) -0.05 per 1% below 20% Max at 100% thirsty is -4.00 m/s
Tanks and Suit
Standard O2 Tank (Paperdoll/Inventory) -0.4 / -0.0 -0.53 / -0.0
HC O2 Tank (Paperdoll/Inventory) -0.47 / 0.0 -0.62 / -0.0
Ultra High Capacity Tank (Paperdoll/Inventory) -0.6-1.21 -0.79 / -1.57 Penalty for carrying in inventory is maxed at 2 tanks.
Lightweight High Capacity Tank (Paperdoll/Inventory) -0.1 / -0.0 -0.13 / -0.0
Reinforced Dive Suit (both pieces) -0.95 -1.24 Other suits have no speed penalty

Note: "Inventory" refers to extra air tanks being carried. "Paperdoll" refers to the air tank that is equipped.

The values above are valid as of build 65786 (Oct-2020) (Tested on Dec 4 2020)