No, SCUBER is not a word it is an acronym and one of its meanings is "Self-Contained Underwater Breathing Apparatus"
The collective noun is a bubble of scuba divers.
Either, depending on context. Usually, if used as a noun it is SCUBA; as an adjective, as in scuba diver, it is just scuba.
'SCUBA' is a noun, referring to the breathing apparatus. 'SCUBA dive' is the verb, with 'SCUBA dived' as the past-tense form.
common noun
Common
Common noun
common
Pea is a common noun, and peas is the plural...still a common noun.
A common noun.
Most definitely a common noun.
300 feet
Camel is a common noun.