8 Faroe islands are connected by 23 tunnels, 4 underwater, and includes the world's only undersea roundabout, nicknamed the jellyfish... are an inspiration to those in the Shetland Islands who realize the ferries aren't sustainable (thank you Stephen! )

Shetland wants to ditch ageing ferries and replace them with undersea tunnels connecting five islands including Unst, the most northerly of the British Isles.

the prime minister of the tiny Faroe Islands, which are 200 miles further out into the Atlantic, points out what a success tunnels have been for them.

At its deepest point the Faroe tunnel is 614ft below the waves and has halved the driving time between the capital and the second biggest town.

"I think we have learned in the Faroe Islands that investment in infrastructure is a good investment," Johannesen told the BBC.

The Shetland island council runs ferry services to nine islands, carrying around 750,000 passengers each year on 12 vessels at a cost of £23m per year.

The average age of the fleet is 31.5 years, costs have risen sharply in the past decade, and some routes are struggling to meet demand for vehicle places.

https://www.bbc.com/news/articles/cvg7jw27w1do