"Full operational, cleared in stealth and satellite recon. All phases of extreme 7 evasives.", Lieutenant James Brody, 2021
Navis 18 Submersible was an armed submarine type used by the UEO around the year 2021. It had stealth capacity and was armed with torpedoes. Navis 18 submarines were also capable of using S-10 defense satellite net for pin-point accurate attacks on any spot on Earth without detection. Although hard to find, once detected Navis 18 submarines were no match for SeaQuest DSV.
In 2021 a group of G.E.L.F. rebels captured a Navis 18 and kidnapped UEO Army General Francis Thomas. The rebels used General Thomas' authorisation to seize control of anti-missile satellite weapons systems number 12 (The Ronald Reagan Memorial Space Base). They demanded recognition of their humanity and equality as citizens and started to destroy air regeneration stations. SeaQuest DSV with help of Lieutenant James Brody, who served on this Navis 18 before and used his code "2 baker 15 victor 7" to locate the sub, could find the submarine and evade all its' torpedo attacks. Captain Bridger then convinced the rebels to surrender.
While they were described as effective attack submarines, with their orbital strike capacities Navis 18 Submersibles might have a role similar to "ballistic missile submarines" in the UEO fleet. It's also unknown how many Navis 18's were operational and what happened to them in late 2020's and early 2030's during the rise of the Macronesian Alliance.
One Navis 18 was seen in the SeaQuest DSV second season episode "Daggers".