A number entering sides of Chinese boat (5)
I believe the answer is:
canoe
'boat' is the definition.
(canoeing is a kind of boating)
'a number entering sides of chinese' is the wordplay.
'number' becomes 'no' (abbreviation for 'number'**).
'entering' indicates putting letters inside.
'sides of' suggests removing the centre (only the letters on the sides remain).
'chinese' with its centre taken out is 'ce'.
'a'+'no'='ano'
'ano' inserted into 'ce' is 'CANOE'.
(Other definitions for canoe that I've seen before include "River craft" , "Boat (that can be dug out!)" , "Ocean (anag)" , "Boat one paddles" , "Simple boat" .)