By Christopher Harvie

A year ago, I crossed a Highland pass where only a grey cycle-track marked the Callander and Oban Railway. Months later on the paddle steamer Waverley we passed a huge German liner tied up at Greenock and a civic planner friend gasped: "Okay, we have these hordes, how do we handle them?" Scotland is going to have a problem coping with 6,000-passenger ocean mastodons, floating Red Roads, loosed from Fort Lauderdale.

But here’s a possible, fundamentally Scottish solution. It ought to be practical to co-ordinate the cruisers with grand veterans like the QE 2 to act as mother-ships for sampler explorations on ships such as the Waverley. The mountains between could have dedicated land-cruise trains.

Our railways have a track record in tourism. Take Oban. In 1881 the Callander and Oban Railway arrived to find that the owner of the main attraction, the town’s hydro, had gone bust. Traffic built up with MacBrayne’s steamers but the hilltop palace crumbled into ruin. Mass tourism, streamlined trains and motor-coaches boomed in the 1930s but their reign was brief: war with its depots, training camps and ammunition dumps would be the big paymaster until 1960, when two Tories, Richard Beeching and Ernest Marples, "rationalised"’ two-thirds of rural lines. Those that survive live off the short summer season.

Meantime the Scots, the great international railway-builders of the pre-1914 era, face a de-industrialised future, while the new lines of a global railway boom aren’t built by low-wage countries but by the Germans, the Swiss, the Chinese and Japanese.

What to do? The answer could lie in the gigantic cruise ships, floating colonies of douce elderly folk viewing masses of people whom they want to trust: a revival which transcends the original "hotel ships", the most disastrous of which – Titanic – launched the trend in 1993. There are problems with heavy-oil pollution, Venetian congestion and potential terrorism but we need to think in policy terms about the opportunity and the spin-offs, in areas where rail development is, in environment and security terms, acceptable and can be fast-tracked. Most of Scotland, in other words.

In May last year, before the reopened Borders Line doubled forecast traffic, National Geographic made me a global vision lecturer and I sailed on its MV Explorer up the west coast: London to Portsmouth, Cornwall to Kerry, the Aran Islands, Donegal, then north to Iona, St Kilda, Orkney, Shetland and over to Bergen. Here it was possible to see the logistics and challenge of cruise tourism, its problems and its potential role in sustaining associated land-transport networks. One example: our modest-sized 7,000-ton ship filled Iona for an afternoon.

The cruise business is growing rapidly but its Scots "shore dividend" equals a tartan tammy (about £5) per passenger and "cheeri-bye!".

So why not organise "Scotland-taster", all-weather one-day cruises and cruise-trains? Border Railway steam specials and Scottish Railway Preservation Society excursions are useful prototypes and a dedicated organisation could use these to secure as spin-offs the future of the far-north lines and accelerate key reopenings elsewhere: the Spey Valley from Keith to Aviemore as the "Whisky Railway" or Aberdeen to Ballater as the "Balmoral Express"?

Such a programme could be used to up-skill young workers and re-technologise much of our further education for use in the development of our "marine regions" in power generation, counter-inundation, aquaculture and conservation.

The far-north lines, radiating from a major anchorage in the Cromarty Firth, have had periodic investment booms (field sports, wartime, nuclear, oil) leaving capacity for co-ordinated development. This can still embrace rail, bus, ferry and air. There has to be an effective multi-mode basic service with interchangeable bus/train tickets.

Further policy has to be bold, offering two to five-hour land-cruise modules with imaginative "Rocky Mountain"-style, year-round programmes and investment in (for example) key links such as the efficient Tain-Dornoch cut-off combining with the highly-scenic Lairg loop.

Dreams, mere dreams? Twenty years ago, the Bernina Pass, Chur-Tirano line in Switzerland was an elderly, near-empty tram. Now there's a vistadomed glacier express each way every hour, plying the Engadine in all weathers. Only weeks ago Ireland's 10-car "Grand Hibernian" was delivered from Kilmarnock to Dublin.

Your worst fear? Well, there's only one Michael Portillo ...

Christopher Harvie is a former SNP MSP, former president of the Scottish Association for Public Transport and founder member of the Scottish Railway Preservation Society.