Potentially open to battering like yachts after a storm’s beginning (10)

'potentially open to battering' is the definition.
(able to be assailed or battered)

'like yachts after a storm's beginning' is the wordplay.
'like yachts' becomes 'sailable' (yachts can be sailed).
'after' is a charade indicator (letters next to each other).
'beginning' says to take the initial letters.
The initial letter of 'storms' is 's'.
'a'+'s'='as'
'sailable' after 'as' is 'ASSAILABLE'.