| Alan Stewart Frame | Director | 1 Feb 2011 | 12 Dec 2012 | British | 55 years |
| Alexander Brian Cooper Short | Director | 30 Jun 2003 | 1 Apr 2007 | British | 59 years |
| Alexander John Davies | Director | 5 Jun 2017 | 13 May 2025 | British | 44 years |
| Allan Keith Lowndes | Director | 23 Mar 2004 | 31 Dec 2012 | British | 79 years |
| Andrew Peter Hopkins | Director | 6 Dec 2013 | 31 Oct 2016 | British | 61 years |
| Andrew Stuart Mclean | Secretary | 22 May 2008 | 27 Apr 2012 | British | - |
| Anna Hilary Austin | Secretary | 17 Mar 2015 | 31 May 2018 | - | - |
| David Wilson | Director | 1 Aug 2019 | 1 Aug 2021 | British | 62 years |
| Ewan John Henderson | Director | 11 Dec 2018 | 31 May 2019 | British | 58 years |
| Gary Horsfield | Director | 1 Jun 2019 | 18 Nov 2019 | British | 55 years |
| George Daniel Tait | Secretary | 28 Apr 1995 | 2 May 2008 | British | - |
| Giles Robert Bryant Wilson | Director | 4 Sept 2020 | 16 Sept 2020 | British | 53 years |
| Gordon Norman Alan Dron | Director | 1 Feb 2011 | 31 Jul 2013 | British | 66 years |
| Gordon Thomas Simpson | Director | 1 Jun 2019 | 8 Apr 2020 | British | 62 years |
| Grant Edward Gordon | Director | 21 Oct 1992 | 8 Aug 2000 | British | 70 years |
| Helen Gaye Cowing | Director | 13 May 2019 | 20 Nov 2019 | British | 60 years |
| Iain David Short | Director | 17 Mar 2015 | 5 Jun 2017 | British | 45 years |
| James Graham Beveridge | Director | 20 Oct 1991 | 23 Mar 1993 | British | 89 years |
| James Joseph Doherty | Director | 1 Apr 2007 | 19 Nov 2010 | British | 59 years |
| Jeremy Sunder Ede | Director | 1 Feb 2013 | 31 Jul 2013 | British | 63 years |
| John Martin Little | Director | 5 Jul 1993 | 31 Jul 1994 | British | 82 years |
| John Michael Harvey | Director | 7 Aug 2006 | 6 Mar 2020 | British | 70 years |
| John Ricson Broadbridge | Director | 9 Apr 2020 | 16 Apr 2021 | British | 69 years |
| John Wesley Waterman | Secretary | 20 Oct 1991 | 28 Apr 1995 | British | - |
| Joseph Gerard Woods | Director | 20 Oct 1991 | 18 May 1992 | British | 72 years |
| Judith Anne Sommerville | Director | 1 Jun 2019 | 31 Dec 2021 | British | 56 years |
| Karen Louise Forbes | Secretary | 17 Dec 2018 | 30 Aug 2019 | - | - |
| Kirstin Hilary Stobo | Secretary | 27 Apr 2012 | 17 Mar 2015 | British | - |
| Lindsay Margaret Campbell | Director | 26 Aug 2014 | 30 Apr 2018 | British | 56 years |
| Michael Lamont | Director | 31 Jul 2013 | 1 Sept 2019 | British | 66 years |
| Michael Lamont | Director | 20 Nov 2019 | 4 Sept 2020 | British | 66 years |
| Niall Mcleod Howard | Director | 6 Jan 2003 | 5 Aug 2003 | United Kingdom | 71 years |
| Nicholas Alexander Swan | Director | 1 Nov 2004 | 31 Jan 2006 | British | 65 years |
| Patrick Marie Charles Thomas | Director | 27 Oct 2000 | 16 Apr 2003 | French | 79 years |
| Paul Bernard Dollman | Director | 2 Jun 1998 | 31 Dec 2002 | British | 70 years |
| Paul Henry Rochford | Director | 1 Mar 2010 | 1 Feb 2011 | British | 63 years |
| Rita Maria Greenwood | Director | 18 Jan 2022 | 31 May 2022 | British | 58 years |
| Robert Brannan | Director | 9 Sept 1994 | 15 May 1998 | British | 70 years |
| Robert Kennedy | Director | 1 Mar 2004 | 31 Dec 2009 | British | 59 years |
| Simon John Hunt | Director | 1 Mar 2016 | 6 Sept 2017 | British | 55 years |
| Stella Julie David | Director | 31 Jul 2013 | 29 Feb 2016 | British | 64 years |
| Stuart Leslie William Davies | Secretary | 1 Jun 2018 | 14 Dec 2018 | - | - |
| Stuart William Gunn | Director | 28 Apr 1995 | 13 Feb 2004 | British | 74 years |
| Victor Eulogio Jerez | Director | 6 Sept 2017 | 1 Aug 2018 | British | 61 years |
| William Burnfield White | Director | 31 Jul 2013 | 16 May 2014 | British | 65 years |