Lifeguard’s first inclination to eat up cereal at pools (8)

'lifeguard's first inclination to eat up cereal at pools' is the definition.
I can't judge whether this defines the answer.

'lifeguard's first inclination to eat up cereal' is the wordplay.
'lifeguard's' becomes 'bias' (I can't justify this - if you can you should believe this answer much more).
'first inclination' becomes 'l' (bst letter of 'lination').
'to eat' is an insertion indicator.
'up' is a reversal indicator (in down clue: letters go upwards).
'cereal' becomes 'oat' (oat is a kind of cereal).
'bias' placed around 'l' is 'blias'.
'blias' reversed gives 'sailb'.
'sailb'+'oat'='SAILBOAT'

Can you help me to learn more?