So, essentially, I need a vehicle with the following things:

Can drive on land, underwater, on water, and in the air
Has most basic rescue equipment
Requires no DLC to use
Can go really fast, but also able to have a mode with manageable speeds
Is pretty small-small enough to explore the caves in-game
Uses only keybinds
Emits a LOT of light
Doesn't show a performance warning when I spawn it
Uses VTOL, but also has an airplane mode