The unclued lights (one doubly hyphened) share a medical similarity. (Despite appearances there are no rude words in the puzzle!)
 

Across

 
3    Revolutionary clock setting? (12, two words)
11    Vessels from fleet in the States (4)
12    When a name is misrepresented? (7)
16    Caught bird, reportedly, on rock (5)
18    Oarsman’s swimming style (6)
20    33’s code-words (5)
22    Some disc analysis? (4)
23    They’re up-beat as he leaves vehicles (5)
25    Singer I left let out gleeful laugh (7)
26    Could be wrong about report on Roe (11, three words)
30    Unidentified male in loo with money, we’re told...