Diver
What you'd actually do
As a diver, you go underwater to do a job - maybe inspecting a bridge underneath the water, checking a pipeline, searching for something lost, or helping scientists study the sea. You wear a special suit and breathing gear and you work in conditions that look like nothing you see on land. The work can be dangerous, so you follow strict safety rules and you stay in constant contact with your team above the surface.
Dives can last a few hours and need careful planning. You learn about the underwater environment, check your equipment is perfect, go down, do the job - which might be taking samples, measuring something, or fixing something - and come back up. You need to be calm and good at concentrating because you are in an extreme environment where mistakes matter. You work with scientists, engineers, and other specialists who depend on the data and observations you gather.