go right under

[keannu]

What does this "right" mean here? The whole thing means "go down", so does "right" mean "immediate"?

st93)She swam breaststorke and kept her head above the surface, not ready to go right under until she had felt safe. After a few strokes she stopped swimming and streached out a foot for the bottom...

 

[Route21]

To go right under means to go completely under.

Regards
R21

 

[5jj]

To go right under means to go completely under.

A meaning that most dictionaries give - see Adverb.6 here.