| Alfred Philip John Malt | Director | 1 Nov 1991 | 25 Mar 1996 | British | 85 years |
| Andrew Christopher John Noble | Director | 9 Apr 2015 | 1 Mar 2017 | British | 65 years |
| Charles Edward Carlson | Director | 25 Jan 1995 | 1 Jul 1997 | American | 94 years |
| Daniel Keith Mazany | Director | 24 Jan 2000 | 20 Sept 2005 | American | 80 years |
| David Arthur Mcalister | Director | 6 Jun 2001 | 30 Mar 2004 | American | 71 years |
| David Mark Hankin | Secretary | 31 Oct 2013 | 24 Mar 2016 | - | - |
| Eric Charles Burton | Director | 6 Oct 1998 | 31 Jan 2010 | British | 81 years |
| George William Mackellar | Director | 14 Feb 2000 | 14 Aug 2006 | British | 66 years |
| Gregory Kane | Director | 3 May 2018 | 22 Jul 2021 | British | 50 years |
| Gregory Richard Ayres | Director | 22 May 2003 | 28 May 2010 | British | 76 years |
| Ian Corrie Thompson | Director | 13 Jun 1995 | 25 Jun 1996 | British | 82 years |
| Jack Thomas Hill | Director | 22 May 2003 | 9 Jun 2005 | British | 83 years |
| Jack Woods | Director | 6 Oct 1998 | 1 Nov 2000 | British | 78 years |
| James Porteous | Director | 1 Feb 1992 | 25 Jun 1996 | British | 100 years |
| James Porteous | Director | 6 Oct 1998 | 31 Mar 2002 | British | 100 years |
| Joel Herbert Bennett | Director | 6 Jan 1999 | 22 May 2003 | American | 90 years |
| Karen Anne Sewell | Director | 31 Jul 2016 | 15 Dec 2016 | British | 51 years |
| Karen Anne Sewell | Secretary | 15 Dec 2016 | 6 Mar 2025 | - | - |
| Keith Jan Hawksworth | Director | 25 Jan 1995 | 16 Feb 1996 | British | 86 years |
| Malcolm William Kennedy | Director | 1 Nov 1991 | 16 Apr 2003 | British | 91 years |
| Mark William Naysmith | Director | 9 Apr 2015 | 16 Dec 2024 | British | 60 years |
| Michael Lister Cunliffe | Director | 1 Nov 1991 | 25 Jun 1996 | British | 91 years |
| Michael Patrick Rogerson | Director | 9 Apr 2015 | 3 May 2018 | British | 60 years |
| Nicholas William John Flew | Director | 19 Jan 2010 | 4 Jun 2013 | British | 66 years |
| Nikolas William Weston | Secretary | 31 Oct 2013 | 31 Jan 2016 | - | - |
| Paul Cheesmond | Director | 1 Jul 1997 | 29 Mar 2007 | British | 76 years |
| Paul Cheesmond | Director | 1 Nov 1991 | 16 Feb 1996 | British | 76 years |
| Paul Richard Nagle Jr | Director | 25 Jan 1995 | 6 Oct 1998 | American | 81 years |
| Philip Richard Martin | Director | 14 Oct 2003 | 20 Jan 2006 | British | 69 years |
| Richard Allen Schrader | Director | 22 Feb 1999 | 25 Jan 2000 | American | 76 years |
| Richard James Proctor | Secretary | 7 Jan 2010 | 31 Oct 2013 | - | - |
| Robert Graham Bruce | Director | 1 Nov 1991 | 30 May 1995 | British | 83 years |
| Robert Ian Maclean | Director | 31 Jul 2016 | 17 May 2017 | British | 67 years |
| Robert Michael Morris | Director | 22 May 2003 | 28 May 2010 | British | 67 years |
| Sally Partridge | Secretary | 31 Jan 2016 | 15 Dec 2016 | - | - |
| Stanley John Embleton Davidson | Secretary | 1 Nov 1991 | 8 Jan 2010 | British | - |
| Stephen Christopher Reynolds | Director | 22 May 2003 | 28 May 2010 | British | 71 years |
| Stephen Derek Bingham | Director | 21 Jan 2010 | 31 Jul 2016 | British | 67 years |
| Stephen John Reffitt | Director | 5 Oct 2011 | 4 Dec 2015 | British | 68 years |
| Terence Alexander Charles Dulley | Director | 1 Nov 1991 | 30 Jun 1995 | British | 89 years |
| Timothy John Matthews | Director | 13 Oct 2003 | 14 May 2007 | British | 75 years |
| Vikram Rajaram Limaye | Director | 19 Jun 1996 | 28 Jan 1999 | American | 80 years |
| William Montgomerie Ritchie | Director | 14 Feb 2000 | 31 Dec 2006 | British | 82 years |