Theme: The Cousteau Collection - the latest thing in swimwear.
16A. Ineffective executive, metaphorically : EMPTY SUIT
20A. Flashy '40s-'60s Cadillac features : TAIL FINS or one word, tailfins.
35A. Underwater activity that requires the ends of 16-, 20-, 53- and 58-Across : SCUBA DIVING
53A. Identity-concealing attire, in a Dumas novel : IRON MASK. (Further info: Wiki)
58A. Brainstorming institution : THINK TANK
Argyle here. A thinking man's puzzle, although I overthought many clues yet there were some I couldn't think of the answer with out perps. 6,7,8 columns in the corners gives the grid an interesting look.
Across:
1. __ as a bird : FREE
5. Marina vessel : BOAT
9. Sudden fancy : WHIM
13. Civil rights icon Parks : ROSA
14. Scandinavian capital : OSLO
15. Ballerina Shearer : MOIRA. We had Moira Kelly last month and Moira Shearer in June. She has been clued as a ballet dancer and/or an actress.
18. Greek i's : IOTAs
19. Window insert : SCREEN
22. Creates, as a word : COINS
23. "Bad" cholesterol letters : LDL. (low-density lipoprotein)
24. Acapulco aunt : TIA. Spanish
25. Qty. : AMT. (amount)
26. Olden times : YORE
30. Auto collision safety device : AIRBAG
32. Ninnies : MORONS
34. Mozart's "__ kleine Nachtmusik" : EINE
38. TV's "__-Team" : THE A
40. Move around an axis : ROTATE
41. Ouija board event : SEANCE
44. Mess (with), in slang : FUTZ. I'm not touching this one.
45. Saint-Tropez sea : MER
48. End of a bray : HAW. Hee-Haw.
49. Egg cells : OVA
51. Fling with effort : HEAVE
56. Got money for, as a check : CASHED
57. Composer Ned : ROREM
60. City NW of Muskogee : TULSA
61. Steakhouse request : RARE
62. "What __ is new?" : ELSE
63. Criteria: Abbr. : STDS. (standards)
64. Med. school subject : ANATomy.
65. In a little while : SOON
Down:
1. Citrus-flavored diet drink : FRESCA. Fresca, a diet lime and grapefruit citrus soft drink made by Coca-Cola, relies on a relatively small but loyal customer base.
2. "You've Got Mail" genre : ROM-COM. Romantic Comedy.
3. __ de corps: camaraderie : ESPRIT
4. All gone, dinnerwise : EATEN
5. Cap'n's underling : BOS'N
6. Sch. in Columbus : OSU. (Ohio State University)
7. Landed : ALIT
8. Sum : TOTAL
9. "Arf!" : [WOOF!]
10. Had a huge success : HIT IT BIG
11. Tehran native : IRANIAN
12. Part of many a spa package : MASSAGE
15. Pop music's __ Vanilli : MILLI
17. "Who me?" reply : "YES, YOU!"
21. Boise's state: Abbr. : IDAho, the "Gem State".
27. Heavenly sphere : ORB
28. Stadium din : ROAR
29. __ an era : END OF
31. Thinker Descartes : RENÉ. A thinking man.
32. Thom of shoes : McAN
33. In __: as found : SITU
35. San Diego marine mammal park : SEAWORLD. (SeaWorld)
36. Winery container : VAT
37. Violinist Perlman : ITZHAK
38. Some have V-necks : T-SHIRTS
39. Listen to without interrupting : HEAR OUT
42. Punctuation in many lists : COMMA
43. Actress Longoria : EVA
45. Hawaiian thank-you : MAHALO
46. Be that as it may : EVEN SO
47. L'Oréal hair care brand : REDKEN
50. Stars, to Caesar : ASTRA
52. Politician Kefauver : ESTES. Running mate of presidential nominee Adlai Stevenson.
54. Loch of legend : NESS
55. Kublai __ : KHAN
56. Tech news website : CNET. It is not (Centre National d'Études des Télécommunications), it is C|net Networks but what that means, I don't know.
59. Fund for the golden yrs. : IRA. (Individual Retirement Account)
Argyle