If movie director James Cameron's 11km dive to the bottom of the Mariana Trench hasn't thrilled you just a little bit, what on earth are you doing reading an engineering magazine? But more to the point, isn't it just generally exciting as a piece of human exploration?

It has become rather commonplace (and tedious) to sneer at big ideas like this. And then, at their accomplishment. Ask Newt Gingrich. Probably the most technologically engaged of all the prospective Republican presidential candidates, he took it in the neck for suggesting that the US establish a base on the Moon.

Yes, he was trying to gather votes in Florida's space corridor, but those who know how closely Gingrich follows all things geeky also knew that (unlike some of his predecessors), he wasn't being entirely cynical. He gets the connection between setting big goals and the fostering of innovation.

Now, it's Cameron's turn. The Mariana dive was a rich man's outing, much like that fella who went to Mir. It won't tell us anything, it won't change anything, it will simply further stuff the bank balance of the world's richest filmmaker. And yes, there is both a TV special and - inevitably - a 3D movie on the way.

Well, hang on there. First off, the technology used in Cameron's Deepsea Challenger submersible may well now find uses in commercial deep sea exploration.

Second, it pushed the limits of marine engineering (and comms as well given that Cameron was able to tweet from the bottom of the world). Compressible syntactic foam - I doubt we've heard the last of that. But in the broadest sense, pushing the limits is how it should be.

Third, the samples. Yes, there have been robotic visits to the Mariana before, but this is an area 50 times bigger than the Grand Canyon. Who knows what Cameron might have literally picked up?

Sure, the director's wealth meant that he could afford to underwrite much of the cost. But what else would you have him do with it? People, this is still all about discovery and, given the parlous state of most world economies, if the phenomenally well-off are not prepared to engage in that right now, it's hard to see who will.

And yes, I'm dying to see what Cameron saw. The last manned expedition to the site, 52 years ago, used state-of-the-then-art technology but on landing the submersible kicked up so much silt, its two occupants could see little outside. Now we will get a chance, albeit vicariously, to visit the Mariana trench in 3D, and for once something in that tired format has got me buzzing. Indeed, the last time I actually did hanker after a 3D movie, it was Werner Herzog's Cave of Forgotten Dreams which also took us to a 'closed' place: the Chauvet Cave in France with its ancient art that would fade from view if exposed to public visits.

Beyond that, I really want to know how they built the submersible, or at least a bit more than the gnomic specifications out there right now. Certainly, it's a pity that the site for the designers at Australia's Acheron Project's remains resolutely password protected, but I suspect the documentary will be a little more revealing.

This is an alien world and we've sent a man there to document and explore it. You don't get many real 'WOW' moments these days - but this is unquestionably one of them.