Low point provides new attitude about depth (5)
I believe the answer is:
nadir
'low point' is the definition.
(I've seen this before)
'new attitude about depth' is the wordplay.
'new' becomes 'n'.
'attitude' becomes 'air' (I've seen this before).
'about' means one lot of letters goes inside another.
'depth' becomes 'd' (abbreviation in geometry).
'air' placed around 'd' is 'adir'.
'n'+'adir'='NADIR'
'provides' is the link.
(Other definitions for nadir that I've seen before include "extremely low position" , "Low spot" , "Low-water mark" , "You can't sink lower!" , "Given lowest place" .)