A 165-metre-long submarine, a tetrahedron-shaped hydrofoil and a vessel by Zaha Hadid feature in this roundup of yacht designs that have sought to disrupt the high-end boat industry.
There's nothing more synonymous with the super-rich than a luxury yacht, and with the industry already valued at $9 billion and expected to grow significantly in the coming years, manufacturers are continually seeking ways to make their boats stand out from the crowd.
Sometimes that means designs that seek to have a smaller environmental impact than conventional boats, with some of the examples featured below powered by hydrogen or solar cells.
Otherwise, it means bombastic concepts that break the mould of the standard pleasure yacht, targeting ambitious forms and functions. Read on for the full list:

Migaloo M5 by Migaloo
Austrian company Migaloo has a vision for the ultra-rich to enjoy private underwater adventures with its recently unveiled design for a 165-metre-long submersible superyacht.
The Migaloo M5 would cost $2 billion and be capable of descending 250 metres below the ocean's surface for up to four weeks at a time. Its design features a swimming pool, gym, cinema and helipad.
Find out more about the Migaloo M5 ?

Tetra by Jonathan Swinge
Taking its name from its distinctive shape, Tetra is designer Jonathan Schwinge's concept for a superyacht that would lift itself above the water while travelling at high speeds using hydrofoil technology.
"The design is instigated by the re...