The Underwater Jet is one of the most difficult vehicles to handle. Luckily it is voluntarily. You can also reach everything swimming and diving, although the Underwater Jet will make the journey much shorter and you can use it's handy weaponry (it uses Harpoon Gun ammo).
- To grab the underwater jet, just swim to the handle and press Action.
- To move the underwater jet, press Jump/Dive and the Directional Buttons.
- To let go press Roll and left or right.
- To fire the harpoons press Action.
- There is a bug involving the Hydro Propeller that enables Lara to fly.
A similar vehicle, the Underwater Sled, is also present in the Cradle of Life film, which Lara and her cohorts use to travel to the Luna Temple. The vehicles are eventually destroyed by agents from the Shay Ling.