To increase the ability to swim faster you must get to your Lifepod, and craft some fins with your crafter, but you will need a material, such as 2x silicone rubber.
You find silicone rubber in the clusters of Creepvine seeds, which are plants similar to seaweed, they are red or bright pink when you have them in sight, you approach them and with the interaction button you take a group of seeds
To get them go to your manufacturer and select "resources" "basic materials" select silicone cube to get 2x.
To make the fins go to "personal" "equipment" "fins", once you have them they are equipped automatically and increase your swimming speed by 15 percent.
I hope that with this article you already know how to swim faster in Subnautica Below Zero, making your fins and increasing your swimming ability and you can venture to other territories by sea.
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