They are the Museums and Heritage Award for Excellence 2006 in two categories - conservation/restoration and permanent exhibition; and the Civic Trust Award 2006. A visit to the ship shows exactly why it has been triumphant.
And Tanner, the director since 2000, has high expectations of what the Gulbenkian award in particular will mean for the museum's future. From the bread and butter of increasing visitor numbers, to encouraging more interest in ships, to bringing ships more in line with the museological agenda, the ss Great Britain has a lot riding on it.
When the Gulbenkian announcement came last month at the HQ of the Royal Institute of British Architects in London, some of the staff who had travelled from Bristol burst into tears.
The night before I arrive to become one of the many journalists knocking on Tanner's door at the moment, the entire staff and volunteers had a celebratory dinner aboard the ship in the first-class dining saloon. On deck, the evidence was still lurking - a stray champagne flute.
Tanner prides himself on the closeness of the staff to each other and the finished product. 'There was a sense of absolute unity from everybody in the organisation that they had all contributed to the vision. I really felt very warm.'
By the time he took on the role of director he says he was clear about his leadership style. But it was at the Great Britain that he learned the art of bringing his staff with him through his own decision-making.
'I was probably a little too fast when I started. I think I grew in confidence, in being able to make firm, clear, timely decisions in a way that brought people together and got them excited as opposed to shutting them out.'
He was first employed by the ss Great Britain Trust as curator in 1997 to conserve the ship. His post was paid for by the Heritage Lottery Fund (HLF) and Tanner says the trustees were unusual in that they embraced change. The fact was they had little choice.
A previous HLF application had been rejected, but the HLF had presented an idea to fund the post that would devise a conservation plan for the ship. The Great Britain was in a sorry state and there was no other option, if saving it was the goal, but to accept what was on the table.
Tanner's belief in a leader 'taking a view' as opposed to design by committee was cultivated over his ten years in the sector. But the ride wasn't always smooth. While studying classics and history at the University of St Andrews in Scotland, he discovered the maritime studies department by accident and knew instinctively that was what he wanted to do. He gained a diploma in maritime studies then went on to do an MPhil on the policing of fishing in the 19th century.
To help financially, he took a job as a museum assistant at the Scottish Fisheries Museum in Fife. Tanner says it was a small museum with a national significance, which had a 'very strong sense of place' and was wedded to a history and heritage that was struggling and dying.
'For a young English boy coming in purporting to know anything about what they were doing was very difficult.' In the three years he was there, he graduated to curator level mentored by two trustees with curatorial experience.
'I really liked on the one hand the academic rigour, knowing and understanding the subject or the audience. But to deal with anyone who comes through the door, you have to be able to communicate with them at whatever level that requires. That skill is something that academics are not usually good at, but it is something I really enjoy,' he says.
After becoming the curator, he rebuilt and redisplayed the 18 galleries within the museum, along with the then director. But he was keen for change and he says one of his main achievements was helping the trustees to see that the collection they cared for was 'outstanding' and encouraging more of an outward rather than an insular view.
Tanner then moved on to a very different beast - what was then called National Museums and Galleries on Merseyside and is now National Museums Liverpool. He became the curator of maritime technology, which he describes as the dirty, industrial end of the ships and boat world.
He was submerged, for the first time, into a world of bureaucracy. Form filling and persuading committees to do things was a huge part of the job.
'I questioned it all the time and didn't make friends because of that.' He says he became frustrated at times at such constraints. He missed the ease of coming up with a good idea and following it through. 'There were too many hurdles in the way of good ideas, which I thought was a shame.'
He was at Liverpool during director Richard Foster's tenure and though they weren't friends he says Foster was respected and accessible. From his own experience now as a director, he understands the high-wire act and tension the position can bring.
'That need to be a leader and to be seen to be a leader is very important, so that you are shaping the vision and giving direction to everybody quite strongly. And often that means you have to be quite up front about it. You have to eliminate your own doubts in order to be clear, to give everybody else a direction. But those doubts don't go away. You have to live with them.' He says this has to be borne in order to be a strong leader.
Otherwise, he says the danger is to descend into a number of committees where no decisions are made. 'As we have seen here [at ss Great Britain] it is delivering that turns on staff and volunteers.'
At Liverpool, he curated more than 100 ships and boats, but had difficulty in finding an accessible way of displaying them. He discounted a static gallery display or putting them on the water where only a portion of the boat is visible. He began to explore the idea of a mirror glass sea in the gallery. But it never came to fruition, as he was unable to secure funding.
That untested idea was the one he took with him to Bristol and the story that followed is now well-known.
Since the ship was relaunched exactly a year ago, visitor numbers are up by 95 per cent on average, says Tanner. After the award, visitor numbers have jumped by an amazing 130 per cent and the museum is running at capacity. The announcement of the prize coming a week before school half-term didn't hurt.
You might think after this success that Tanner would be itching to move on, but he says not. His focus now is the phase-two development, behind the site of the Great Britain. Bristol City Council has given the land to the trust (at a reduced rent) and the trust will use the development to create an endowment fund to re-invest into the museum.
In partnership with the University of Bristol, a Brunel Centre is proposed that will incorporate an archive, library, and learning centre and lecture theatre complex. 'There was a danger that having put so much emotion and energy into delivering what's outside now, there could have been a great deal of disappointment that this might be the end and the team would have to split up.'
There is also the matter of where a man who is most comfortable in the independent sector will move to. At this year's Association of Independent Museums (Aim) conference, and as secretary of Aim, he gave a frank speech that he seems keen to tell me about.
He is irked by the fact the ss Great Britain, a registered museum, is not funded by the local authority or national government and fails to fit the Renaissance in the Regions regimen. The trust is in discussion with the Museums, Libraries and Archives Council (MLA) about this.
Another cause of contention is the fact that the trust has applied on two occasions to become Designated and has been rejected. The explanation given by the previous MLA administration was that the ship was not a collection.
Tanner argues: 'The spirit of Designation is about the national and international importance outside the scope of the national museums. We were not very happy about that.'
Tanner hopes that the Gulbenkian will change its fortunes in these departments. But that's not all. He wants to use the Gulbenkian Prize to push the case for historic ships and show that they are 'good and can be really exciting for everybody'.
And he wants their relevance to be clear. 'The popular myth is that we don't have ships any more because we don't go to sea anymore. In fact, the reverse is the case.' Ninety eight per cent of trade is by sea, he says.