The dotted line

Hugh Pearman cruises with the glitterati at the launch of Tate to Tate, a new river shuttle service that links the Thames-side galleries

There we all were on the boat – Sir Nicholas Serota of the Tate, Damien Hirst, the pranksterish conceptual artist, David Marks and Julia Barfield, architects of London Eye fame, Mayor Ken Livingstone, and assorted camerafolk and hacks including me.

And why were we there? Because it was the inauguration of ‘Tate to Tate’, a moderately high-tech riverbus service between Tate Britain on Millbank and Tate Modern downstream at Bankside. Calling at County Hall on the way, for the new Saatchi Gallery and, of course, the London Eye.

So what’s the big deal? Well, there are meant to be three big deals, of which two are real. Big deal one is that the Tate has managed to get the sponsorship to subsidise a boat shuttle at all, let alone one of this quality – this is one hell of a boat, a sleek, stable, fast, large-capacity Australian-built catamaran with a café on board. Big deal two is the new Millbank pier from which it departs. Riverboat piers tend to be dull affairs, essentially huts stuck on top of pontoons. Not this one, designed by the aforementioned Marks and Barfield. It is a real piece of architecture, from the long elegant truss of its obliquely angled approach ramp to the steel origami of its structure, which ingeniously folds itself into a timber-lined shelter.

Marks and Barfield have rethought the whole idea, even having purposeful-looking hinged steel struts to hold everything in place as it moves up and down with the tide – instead of the conventional, clumsy vertical piles. It’s got a nice integral lighting scheme, designed with artist Angela Bulloch. So this pier doubles as a pier in the other sense – a place to promenade, over the water. It’s a pleasure to use.

Big Deal Three is PR hype. The boat is decorated by Damien Hirst. With his trademark coloured dots. Mostly on the outside, but inside the white antimacassars on the seats also each bear a single Hirstian dot. Hirst smirked and gurned for the cameras on the trip, but really – you’d have thought he might at least have done something clever with sharks in this context. Then again, think what Tracey Emin might have made of those seat covers.

So hats off to the sponsors who have finally delivered the Tate’s dream of linking its two powerhouse galleries on the river. The capital cost of the new pier alone is £1.8m, while the subsidy to the boat operator is considerable. But there’s a catch: this boat, like all the others on the river, is not truly integrated with the transport network. You have to buy a £4.50 day ticket to use it. A London Transport Travelcard reduces that cost to £3, but it’s still likely to put many people off. It’s a reverse congestion charge – you pay extra for NOT using the roads.

Oh, and as there’s only one boat, you may find yourself having to wait up to 40 minutes before it comes along. Which will put more people off. But it’s a great experience. You’ve got three years to enjoy it before the subsidy runs out.