The Stinger
A one-man submersible developed aboard seaQuest: the small fast craft that lets a single crew member go do something the boat is too large to do.
Details
A small high-speed single-occupant submersible, and unusually for the show's hardware we watch it being designed: season one's "The Stinger" turns on Lucas and Hitchcock competing over the design, with the test programme going wrong once a rival developer takes an interest.
It serves the obvious narrative purpose too: it detaches one character from the ensemble and puts them somewhere dangerous alone.
Editor's note: specifications and any later appearances are still being logged.
Real-Life
Wet submersibles are the direct equivalent. SEAL Delivery Vehicles carry divers who remain in the water, breathing from onboard supply, flooded rather than pressurised: the Mk 8 SDV being the long-serving example. They launch from dry deck shelters mounted on host submarines, which is precisely the seaQuest arrangement.
Dry combat submersibles took much longer. Keeping the occupants dry and at one atmosphere is far harder than it sounds, and the programme history is a catalogue of cancellations: the Advanced SEAL Delivery System was abandoned in 2009 after cost overruns and a battery fire. The Dry Combat Submersible eventually entered service around 2019, roughly two decades late.
Diver propulsion vehicles are the small end. Handheld and rideable scooters extend a diver's range and conserve gas, used routinely in technical and cave diving as well as military work.
The uncrewed version overtook it. The direction of travel has been to remove the occupant entirely. Boeing's Orca XLUUV is a large autonomous submarine designed for long independent missions (mine-laying, surveillance, payload delivery) with no one aboard. Anduril's Dive-XL and similar platforms pursue the same concept. The small craft launched from the mother ship became real; the pilot inside it is being designed out.
Human-powered and swimmer-delivery history. The lineage runs back to wartime chariots and X-craft midget submarines, and the ISR class of Italian maiali: the idea of detaching one or two people to do close work is among the oldest in submarine warfare.
