Surfie to go bare? He needs zinc on bum smeared! (9)

'zinc on bum smeared' is the definition.
I know nothing about this answer so I cannot tell whether it can be defined by this definition.

'surfie to go bare? he' is the wordplay.
I cannot quite understand how this works, but
'go' is found in the answer.
'he' could be 'che' and 'che' is present in the leftover letters.
The remaining letters 'bear' is a valid word which might be clued in a way I don't understand.
This explanation may well be incorrect...

'needs' acts as a link.

Can you help me to learn more?