"These futuristic Royal Navy submarine concepts look..." Topic

… and act like fish.

"Skip back 100 years and the world of warfare today looks almost unrecognisable. You'd think that would make predicting what military vehicles will look like in the future nigh-on impossible, but Britain's Royal Navy has other ideas.

Its Nautilus 100 imagines the submarines and micro-drones that will be patrolling our oceans in 50 years. The work was commissioned to mark the 100th anniversary of the USS Nautilus, the world's first operational nuclear submarine.

"The underwater battle space is a hugely challenging environment and it's predicted to remain so for a long time yet," says Peter Pipkin, the Royal Navy's fleet robotics officer. He continues to say the vehicles used in the future will be more autonomous and make use of other technologies still in development…"
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Amicalement
Armand

One of them looks a bit like a large version of the "Flying Sub" from "Voyage To The Bottom Of The Sea".

More sci-fi/fantasy rather than practical – at least as of the near term…

Agree!

Amicalement
Armand

"Operating in the underwater space is incredibly difficult, just sharing communications is difficult," Pipkin says. "Using a family of vehicles, or a swarm of unmanned underwater vehicles, can extend that communications range and create networks that form themselves."

Anyone else see the logical disconnect here?

"We can't talk underwater, so we're going to use a swarm of vehicles (that need to talk to each other)"

Though technically the problem is that you can't talk *covertly* underwater. If you talk, everyone in the ocean can at least hear that someone is talking, even if you use some fancy encrypted system so that they can't hear what you're saying.