Craft needing personal attention, you understand? (9)
I believe the answer is:
privateer
'attention you understand?' is the definition.
I can't tell whether this definition defines the answer.
'craft needing personal' is the wordplay.
'craft' becomes 'er' (I am not sure about this - if you are sure you should believe this answer much more).
'needing' means one lot of letters go next to another.
'personal' becomes 'private' ('private' can be similar in meaning to 'personal').
'er' put after 'private' is 'PRIVATEER'.
(Other definitions for privateer that I've seen before include "Government-sanctioned pirate" , "Armed non-government vessel commissioned for war" , "Government-commissioned vessel authorised to prey on enemy shipping" , "Privately-owned warship" , "Armed ship used in war but not government-owned" .)