ACROSS
6 - Abandon supply… (5) - YIELD [DD]
7 - … to the Massachusetts whaling town made famous by limericks
(9) - NANTUCKET [GK]
There once was a man from Nantucket
Who kept all his cash in a bucket.
But his daughter, named Nan,
Ran away with a man
And as for the bucket, Nantucket.
10 - Deliver note sent ahead by the UP leader in the midst of rocks at the cliff base (6) - RESCUE (+re){RE)(SC{U}(-re)E}
11 - Mother ignored bottom plate put outside in the sink (8) - DIMINISH {D{IM}{IN}ISH} ? Anno pending (Addendum - {DI{MINImum}SH} - See comments}
12 - Piercing jewellery piece of the harsh judge thrown out by the
Earl (7) - EARRING (-j+e)EARRING
13 - Sees Cuban hiding some diving gear (5) - SCUBA [T]
14 - Quantity of something about which no one is certain (7) - UNKNOWN [E]
15 - Witty joker goes back with cooked ham for some Greek money
(7) - DRACHMA {DRAC<-}{HAM*}
18 - John, in speaking to the police department, was comprehensible
(5) - LUCID (~loo){LU}{CID}
19 - Revolutionary eventually gets rigorous imprisonment in the
repeat hearing (7) - RETRIAL {RET{RI}AL<-}
20 - Dangerous racists settle around the island over a geological
timescale (8) - TRIASSIC {TR{I}ASSIC*}
22 - Initially place lumber inside nursery to help with the column
support (6) - PLINTH {P}{L}{I}{N}{T}{H}
23 - Sluggard scratching head with some smoothing tools used by
manicurists (9) - NAILFILES {sNAIL}{FILES}
24 - Spirit found in a Tianjin nightclub (5) - JINNI [T]
DOWN
1 - Score: -1 (8) - NINETEEN [E]
2 - On-screen letter? (10,4) - ELECTRONIC MAIL [CD]
4 - Scrap one of the Intel microprocessor lineups (4) - ATOM [DD]
5 - Studied to find out, we hear, about the Middle Eastern water body
(3,3) - RED SEA (~read){RED} {SEA}(~see)
8 - Conservative's unfortunate junction visit results in ‘Madras Eye'
(14) - CONJUNCTIVITIS {C}{JUNCTION+VISIT*}
9 - Inspected sheep picked up by the underwater worker from the south
(8) - REVIEWED {REVI{EWE}D<-}
16 - Michigan in flames over worker being aggressive (8) - MILITANT {MI}{LIT}{ANT}
17 - Windpipe in painting drawn up by a revolutionary undergoing
imprisonment (7) - TRACHEA {TR{A}{CHE}A<-}
21 - Spotless Oriental making way for the Pole in the hero's tale (4) - SPIC (-e+s)SPIC