It's the 20th anniversary of The Royal Yacht Britannia opening its doors as a visitor attraction in Edinburgh. The former floating palace, berthed alongside Ocean Terminal in Leith, has been voted Scotland's Best Visitor Attraction for a record 12th year in a row – it also features in TripAdvisor's top 5 UK attractions. Here are some facts and figures to help celebrate her 20 years in the capital.

1. Britannia was the only vessel in the Royal Navy to have her own 24-hour laundry. Up to 600 shirts could pass through the washers and dryers in one day.

2. She was the last ship in the Royal Navy where sailors slept in hammocks. The practice continued until 1973.

3. Under the Cold War plan Operation Candid, in the event of nuclear war, the Queen and the Duke of Edinburgh were to take refuge aboard Britannia as she hid in sea lochs on the north-west coast of Scotland.

4. The ship’s wheel came from King Edward VII’s racing yacht. Also named Britannia, it remains the most successful racing yacht of all time.

5. Amongst the family memorabilia onboard is Prince Philip’s driftwood collection.

6. Britannia was designed to be converted into a hospital ship during times of war. Although never used in this capacity, she did successfully evacuate over 1,000 refugees from Aden during the South Yemen Civil War in 1986.

7. A knighting stool was carried on all voyages.

8. All royal children were allocated a crew member as their ‘Sea Daddy’ on board the ship. Although primarily assigned to look after the children and keep them entertained with games, picnics and water fights, these crew members also oversaw the children's chores - which included the cleaning of the vessel’s life rafts.

9. The yacht’s Admiral might have to change uniform up to 12 times a day, depending on his duties

10. ‘Wombat Tennis’ was a favourite game played by officers in the Wardroom. The game began when the ‘ball’, a soft wombat toy gifted to the officers by one of the Queen’s ladies-in-waiting, was thrown up at the ceiling fan and batted from one side of the room to the other.

11. The Queen originally wanted an open fire in the drawing room until she discovered that safety regulations would have required a sailor equipped with a fire-bucket standing next to it at all times. An electric fire was installed instead.

12. When in use, the engine room was kept in such pristine condition that a doormat was provided and visitors were asked to wipe their feet before entering.

13. Instead of the traditional champagne, a bottle of Empire wine was smashed against Britannia's hull at her launch on April 16,1953. Champagne was considered too extravagant in post-war Britain.

14. One of the most treasured items on board is a framed gold button which came from Admiral Nelson’s coat.

15. The Queen Mother would reportedly imitate the sound of Britannia’s blowing foghorns as the ship came into port near her home on the north coast of Scotland, much to the amusement of those nearby.

16. In an effort to maintain Royal order and tranquillity, crew aboard the vessel used hand signals to issue orders and wore soft-soled white plimsolls as a means of reducing noise and disruption.

17. In the Royal Galley there was a special cold room called the Jelly Room, where the royal children’s jellies were stored.

18. In 2005, Bob Downie, Chief Executive of the Royal Yacht Britannia, became the first Scot to receive a UK Hospitality & Tourism ‘Catey’ Award (the Oscar of the hospitality industry.)

19. Before Britannia berthed, Royal Marines would search the seabed and surrounding area for terrorist devices. They would also dive daily under the ship’s hull to make security checks.

20. All the clocks on board remain stopped at 3:01pm, the exact time the Queen was piped ashore for the last time following the ship’s decommissioning ceremony in December 1997.