Last week, to coincide with the launch of the new Jaguar XF Sportbrake, Jaguar revealed what it calls the car’s ultimate accessory, Concept Speedboat by Jaguar Cars.

Now your first instinct may be that this boat, which has so far never sat in the water and which doesn’t even have a working powertrain in it, is a piece of marketing frippery created to grab a few easy headlines. But it’s actually worth delving deeper than that.

The boat’s design is the work of Jaguar design director Ian Callum and his team, and has been treated very much as an opportunity to showcase their talents. While it may not have been toiled over in quite the same way as the new Jaguar F-Type – it was finished just two days before being revealed – Callum’s passion for project is every bit as evident as it is for his four-wheeled creations.

“It’s a statement of what we can do as a design team,” says Callum. “A car is just about the most complicated piece of design in everyday life – there are so many forces at work, be they engineering needs, legislation, cost and production variables or whatever. We have to design with all these factors in mind.

“But with the boat we were freed from that, and I wanted us to show the wider design world what we could do if we applied Jaguar design themes of form, fluidity and clean lines elsewhere. The lines express sleek and fast characteristics, just like our cars. The rear wing mimics the D-Type but is made of carbonfibre to keep high-up weight as low as possible; a modern interpretation of a classic look, if you like. I don’t mind saying that my design team is better now than it has ever been – we’ve grown together, and we want to showcase our talents.”

It’s a serious bit of kit, too. The build process was overseen by Canadian naval architecture consultancy Ivan Erdevicki, and Callum says it was engineered to be powered by a Jaguar V6 diesel capable of a projected 60 knots. While that drivetrain isn’t in there now, there’s no question that it could be if someone gave the go-ahead. “If we built this boat without engineering it to be able to do what we claimed was possible, it would be like building a concept car around a chassis that didn’t exist,” says Callum.

So will Concept Speedboat ever see the water? Officially, the answer’s a flat no. But you have to wonder as to the point of going to such a lot of effort to create something that will never see active service.

In fact, I’d go so far to say that after making so much effort to build a credible concept, Jaguar has no choice but to give it life, even if it’s only to prove a point rather than put it on sale. The boat is a rightful celebration of what the company's design team has achieved now and will do in the future. To my mind, to do anything other than give it a similar level of engineering credibility would risk leaving those with long memories doubting the veracity of similar future ventures.