Personnel boarding damaged boat - it's pulsating (6)
I believe the answer is:
athrob
'pulsating' is the definition.
(I've seen this before)
'personnel boarding damaged boat' is the wordplay.
'personnel' becomes 'HR' (Human Resources).
'boarding' indicates putting letters inside.
'damaged' indicates an anagram.
'boat' with letters rearranged gives 'atob'.
'hr' inserted inside 'atob' is 'ATHROB'.
'it's' acts as a link.
(Other definitions for athrob that I've seen before include "beating" , "all of a twitter" , "Pulsing" , "Pulsating" .)