The seventh annual TEDx, dedicated to “ideas worth sharing”, has seen the popular fixture of local and international speakers expand further after its 18-month “furlough”.

Executive director John Narraway introduced guests who, in their different capacities, asked the question “What if?”

Marine aquaculture researcher David Vaughan sees hope out of the devastation inflicted on coral reefs, 25 to 40 per cent of which have died back in recent decades.

At his Florida labs, Dr Vaughan discovered a quick technique for growing new specimens which, because they all come from the same parent piece, fuse together as they grow.

“We can restore the reefs in our lifetime,” Dr Vaughan told the gathering at the Southampton Princess Hotel. His modest personal goal is to replant a million corals before he retires.

Visitors to Boston may have noticed innovative new designs such as the app that allows citizens to report problems from graffiti to pot-holes directly to city hall.

Such innovations were brought with the help of Nigel Jacob, co-founder of the Mayor’s Office of New Urban Mechanics, which specialises in “building things that people want or need”.

Among Mr Jacob’s simple discoveries: when the troubleshooting app responded with a picture showing the team working to fix the problem, the rates of reporting went up 60 per cent.

Stephen Bliss, an artist whose designs have appeared in the likes of Grand Theft Auto, happily shared his “midlife apocalypse” that prompted him to seek the chance art emerging on the walls around New York.

The juxtaposed images in ripped or weathered layers of posters, or illegal posters painted over in green, jostle with the cryptic messages of graffiti and stickers in the pictures Mr Bliss “harvests”.

Rose Rios, the 43rd Treasurer of the United States, brought applauding guests to their feet with her account of her work to bring a woman’s portrait to US currency for the first time in the nation’s history. The push for equality extends to park statues and the pictures on classroom walls, where children acquire their expectations of themselves as early as the age of 5.

Susan Erdman from the Massachusetts Institute of Technology explored the “love story” of microbes with their hosts, and their power to “grow good health”.

“You have the ability to be what you want to be — and with the science that’s emerging, you make this story your own.”

In exploring the storytelling possibilities transforming film through virtual reality, Joel Newton, CEO of the Congregation virtual reality contest fund, “developed a new hope for humanity”.

Meanwhile, Jake Malliarnos, a physics student at Canada’s University of Waterloo, presented research on a high-speed transportation system to link cities — or hurtling “from one side of Bermuda to the other in just under two minutes”.

Bermuda’s own Irwin Trott closed the day with the Warwick Gombey Troupe, plus a quick history of the art form’s emergence from the African and Native American cultures forcibly brought to the island.

Gombeys, Mr Trott said, wear regalia, not “costumes”: their headdresses and capes are royal attire.

Discovering his own family ties to the Pequot people of the Eastern Seaboard underlined his own passion to pass on the tradition to young people.

TEDx Bermuda has come a long way since the first labour of love in April 2011. Among the latest innovations were question and answer sessions with speakers, and exhibits that ran prior, during and after the main event — and Mr Narraway said plans for the years ahead included turning the seminar into a full-day event.

Bermuda’s talks will be available to view on YouTube in two to three weeks.