There's no technical definition of a 'wave' in cinema. Mostly it's just a convenient and somewhat patronising way of lumping together three or more films that happen to come from a small territory. It matters little whether there's anything other than coincidence to these films' success.
The wide variations in style among the recent run of Romanian films, or indeed this year's festival hits from Israel, surely defy such easy categorisation. Most of the film-makers are adamant that no wave exists.
Now the idea of a Baltic wave has been floated. Two films - both Estonian - have made an impact on the local market and the festival circuit this year. Ilmar Raag's The Class (Klass) and Veiko Ounpuu's wonderful Autumn Ball (Sugisball) have been picking up accolades steadily. What they have in common is largely a micro budget - just over $700,000 and $500,000 respectively - but little else.
Like many of the other Eastern European successes of recent years, what's missing is a local market worth the name. In the long run there may be a style that can be seen as determinedly Baltic, with the founding of a film school bringing together Estonia, Latvia and Lithuania. But turning a couple of successes into a wave requires a considerable amount of work.
After the fall of Communism, a good number of newly constituted states with grand cinematic histories were barely able to make a single film in a year. There are simply not enough screens per head of population and after many years of negligence, most people are not in the cinema-going habit.
A Screen International-backed round-table discussion at last week's Black Nights Film Festival in the Estonian capital of Tallinn pointed to some of the problems. Underpinning the discussion was a fear widespread in emerging film nations: that the attention of the festival circuit will come and go with little to sustain a future.
In Eastern Europe, perhaps the memory of those who fled during the Soviet period to make new lives in the West, such as Roman Polanski, hints at the possibility of global success for a few talented directors but not much of a spin-off for the home country.
Worryingly, the evidence is growing that the supposed trickledown effect of Hollywood production in new studios is not enriching the wider business because the differential in money is just too great.
These things do matter to the business as a whole. It's important for all levels of the industry that film is a truly global form. From a business perspective, the reawakening of Eastern European cinema has huge potential for the international market.
But the Estonian question highlights the problem: you need a base on which to build a sustainable film-making and cinema-going culture. There are three areas that must be at the centre of the discussion.
One is that support at local and European level must focus on ensuring films can be seen as well as produced.
The second is that the opportunities of new forms of distribution are seized. Tallinn is one of the most broadband-enabled cities in the world, yet cinema building is taking precedence.
And finally, the big hope is that local cinema can be drawn into the international market. That change does not have to be at the expense of local culture. The evidence of recent years is that the independent market rewards films with specific locations - geographical, social or cultural.
But it does mean integrating film into the wider world. Autumn Ball producer Katrin Kissa put it perfectly in a recent Screen interview when she described an ambition to 'gain admission into a larger context and be considered as a film, not as a film from some weird, small country'.
The appropriate maritime analogy shouldn't be of creating waves that crash and disappear, but of opening up rivers to flow into a wide ocean.