B1
someone who swims under water, usually with breathing equipment
Dictionary examples:
The clumsy diver accidentally hugged an octopus, thinking it was his diving buddy. (0.0)
The diver forgot his mask and tried to use a fishbowl instead. (0.0)
The forgetful diver left his oxygen tank at home and brought a balloon instead. (0.0)
a deep-sea diver (19.1)