What could account for a 30 per cent increase in overseas visitors choosing to holiday in Scotland?

The welcome boost comes at a time when "staycations" are increasing in popularity, with more people choosing to holiday in Scotland or the rest of the UK as sterling takes a hit in the wake of the Brexit vote.

These figures predate the significant shift in exchange rates as economic jitters follow Britain's vote to leave the EU.

Nevertheless tourism chiefs believe an exchange rate which was already favourable for European visitors may have had a critical role in encouraging almost 300,000 people to travel to Scotland in the first three months of 2016 - up on 206,000 a year earlier.

Visit Scotland is also keen to tout the success of its Spirit of Scotland campaign, promoting the country's attractions within the UK and USA as well as countries such as Germany and France.

But it would have to be one of the most successful marketing initiatives in history to have delivered a 30 per cent increase in activity. Other factors are at play.

It could be that an interest in Scotland has been kindled by the independence referendum, which put the country on nightly news bulletins around the world. Hosting the Commonwealth Games can only have helped, although it may have helped account for why the rolling year on year figures were not so favourable from 2014 to 2015.

Whatever the reason this is excellent news for an important industry to the Scottish economy.

It seems likely that further weakening of the pound could also encourage more overseas visitors throughout the year and may help address a 16 per cent reduction in visits from North America.

Nevertheless there are clouds on the horizon. Any short term benefits related to the Brexit vote could lead to a longer term hangover. Trade renegotiations could lead to changes to UK's status as an air hub, or airline access agreements, contracts with hotels, carriers and ground agents could be affected.

More importantly still, the industry faces longer term difficulties in recruiting and retaining overseas seasonal and permanent staff. We often hear Scotland's need for immigration cited, and warnings of the economic impact if more people cannot be attracted to live and work here. The tourism industry is a timely example of the importance of Scotland taking a different approach from the rest of the UK on this issue.