US Special Operations Command (USSOCOM) has accepted the first Dry Combat Submersible (DCS) from Lockheed Martin with a Lithium-ion Fault Tolerant (LiFT) battery system from General Atomics Electromagnetic Systems (GA-EMS). The DCS is a delivery vehicle for transporting personnel in dry environments over long-endurance intervals. The Lift batteries power the propulsion and internal support systems. The USN has conducted sea-trials of the LiFT system, which is now certified for use on undersea vehicles.
Source: https://www.shephardmedia.com/news/naval-warfare/us-special-forces-receive-dry-combat-submersible-g/