Mini subs

The last time we looked at the U-Boat Worx Nemo submersible, production start was listed as a vague "when market demand has been met." The vessel launched last year, and U-Boat Worx is now commencing volume production and drastically cutting price.

Resting 12,500 ft below the surface, the wreck of the Titanic has rarely been visited by manned submarines. But Triton's latest luxury sub can take you down there in air-conditioned comfort, and it sports a clever set of articulating gull wings.

Dutch submersible maker U-Boat Worx has unveiled what's claimed to be the lightest manned submersible ever built. The Nemo can be towed on a trailer by car for launch from shore, or hauled onto a yacht for underwater fun at sea.

Dutch submersible-building company, U-Boat Worx, claim to have created the world's deepest-diving, fully-acrylic, transparent crew compartment submersible with a diving depth down to 1,700 meters (5,577 ft).

BAE Systems Talisman L is an unmanned, autonomous mini submarine that will help protect ports and coasts from attack.