Deep breath? (3,6)

I think it could be either:

Which length description are you looking for?:

3,6

4,4

sea breeze

I'm a little stuck... Click here to teach me more about this clue!

'deep breath?' is the definition.
The definition and answer can be both types of natural phenomena as well as being singular nouns.
Maybe they are linked in a way I don't understand?

'deep breath?' is the wordplay.
'deep' becomes 'sea' (the deep can mean the sea).
'breath?' becomes 'breeze' (breath is a kind of breeze).
'sea'+'breeze'='SEA-BREEZE'

Can you help me to learn more?

(Other definitions for sea breeze that I've seen before include "Maritime wind" , "Doctor" , "Gentle coastal wind" , "Gentle wind from the ocean" , "Vodka-based cocktail" .)

I've seen this clue in The Telegraph, The Guardian and The Independent.

Want a hint initially instead of a full solution? Install my app