| Andrew James Nicoll | Director | 2 Mar 2016 | 29 Jun 2021 | British | 57 years |
| Ann Elizabeth Hughes | Director | 7 Sept 1997 | 22 Aug 2003 | British | 74 years |
| Anthony John Russell | Director | 1 May 1992 | 30 Apr 1998 | British | 84 years |
| Campbell David Fleming | Director | 11 Dec 2009 | 29 Apr 2016 | Australian | 62 years |
| Clive Frederick Coates | Director | 20 Apr 1995 | 31 Dec 1997 | British | 82 years |
| Colin Edward Parker | Director | 1 May 1992 | 20 Apr 1995 | British | 91 years |
| Crispin John Henderson | Director | 6 Mar 2002 | 28 Feb 2013 | British | 78 years |
| Donald Armstrong Jordison | Director | 13 Nov 2014 | 1 May 2018 | British | 66 years |
| James Anthony Wiltshire | Secretary | 1 May 1992 | 1 Sept 1997 | British | - |
| John Adrian Varcoe Grimshaw | Director | 1 Oct 2007 | 24 Nov 2008 | British | 64 years |
| John Devine | Director | 14 Nov 2008 | 1 Dec 2010 | British | 68 years |
| Madeline Forrester | Director | 14 Jun 2006 | 9 Aug 2011 | British | 60 years |
| Malcolm Hugh David Kemp | Director | 7 Sept 1997 | 15 Jun 2009 | British | 66 years |
| Mark Andrew Burgess | Director | 23 Feb 2011 | 19 Sept 2018 | British | 62 years |
| Michael Austin Taylor | Director | 7 Sept 1997 | 31 Dec 2006 | British | 67 years |
| Michelle Sylvia Scrimgeour | Director | 14 Aug 2017 | 26 Apr 2019 | British | 63 years |
| Nicholas John Kirk | Director | 12 Feb 1997 | 31 Mar 1999 | British | 73 years |
| Paul Victor Sant Manduca | Director | 12 Feb 1997 | 22 Feb 1999 | British | 75 years |
| Peter William Stone | Director | 19 Sept 2018 | 12 Jun 2023 | British | 61 years |
| Philip James William Reed | Director | 1 Oct 2007 | 30 Jun 2014 | British | 64 years |
| Robert Anthony Clark | Director | 1 May 1992 | 21 Jun 1993 | British | 102 years |
| Robert Frederick Hubbard | Director | 1 May 1992 | 31 Jan 1995 | British | 86 years |
| Roger John Brignell | Director | 1 May 1992 | 30 Sept 1998 | British | 80 years |
| Roy Edgar Brimblecombe | Director | 1 May 1992 | 21 Jun 1993 | British | 89 years |
| Sarah Fiona Arkle | Director | 18 Sept 2008 | 23 Feb 2011 | British | 70 years |
| Simon Howard Davies | Director | 12 Feb 1997 | 11 Sept 2008 | British | 67 years |
| Stephen Benedict Cohen | Director | 19 Jul 2000 | 6 Mar 2002 | British | 70 years |
| Stewart Laver | Director | 1 May 1992 | 18 Nov 1992 | British | 77 years |
| Timothy Nicholas Gillbanks | Director | 14 Jun 2006 | 31 Mar 2017 | British | 60 years |
| William David Lowndes | Director | 17 Nov 1998 | 12 Jun 2006 | British | 63 years |