Rate of ocean's retreat (5)

I believe the answer is:

speed

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

'rate of ocean's retreat' is the definition.
'speed' can be an answer for 'rate' (speed is a kind of rate). I'm not certain of the 'of ocean's retreat' bit.

'rate of ocean's retreat' is the wordplay.
'rate of' becomes 's' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'ocean' becomes 'deep' (I've seen this in another clue).
'retreat' is a reversal indicator.
'deep' in reverse letter order is 'peed'.
's'+'peed'='SPEED'

Can you help me to learn more?

(Other definitions for speed that I've seen before include "Hasten" , "Swiftness" , "Race" , "Travel quickly" , "Pace or tempo" .)

I've seen this clue in The Independent.

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.