Only paying passengers on commercial lines available to the general public count, cruises and the like count if the vessel loads and unloads passengers at at least two points 100km apart.
Self-propelled vessels only, excludes hot air balloons.
Do hot air balloons count? If so this question might just come down to how many people fly on commercial recreational hot air balloon flights, which are currently common.
Edit: Maybe they're not so common and I only thought they were because of where I live, where I see them flying over my house regularly. And these trips look like they're less than 100km. (30-50km I see mentioned on one provider's website). But the industry carries 250k passengers per annum in Australia alone, so if even a small fraction of them are over 100km this could resolve YES.
@chrisjbillington it looks like they don't normally reach 100km and 1M by 2050 is 37k a year so we should probably be safe, is anybody against specifying airships to avoid the risk of having to estimate how many balloons travelled 100km?
@CodeandSolder yeah best to exclude balloons I think. It's both hard and not an interesting question to be trying to count balloon flights.