Forget multimillion-dollar superyachts or cruise ships - holidaymakers may one day explore the sea in futuristic vessels that look like flying saucers.
Inspired by the extraterrestrial, a design team from Italy has created a concept watercraft, called UFO (Unidentified Floating Object), that has two half-spherical shells as passenger compartments, which are divided by a floating disc that doubles as a sundeck.
Guests would be able to relax in a lounge in the upper fibreglass shell or head down to the lower shell to shower or admire sea creatures.
Designed by Naples-based marine architects and builders Jet Capsule, the UFO is intended to be a two-storey floating house with a middle disc measuring 12.55 metres (41ft) and a waterline length of 40 metres (131ft).
It looks like an alien spaceship, but owners would be able to customise the exterior and interior to their liking.
The surface of the disc could be used as a garden with grass and trees, sundeck or walking or cycling path, while the interior could hold a kitchen, lounge or luxury amenities that would normally be found in a swanky house, although space would be limited.
A small bathroom would be located on the lower level.
The interior would have 2.2 metres (7.2ft) of head room, while the vessel itself would have a height of six metres (19.6ft).
The designers, led by company co-founders Pierpaolo Lazzarini and Luca Solla, said the floating home can be aligned with a compass, keeping it on course.
Even in rough seas, the UFO would maintain its position and stability safely thanks to a special elastic anchor system, said the designers, who are looking for an investor to create the first working prototype.
They said the UFO is environmentally-friendly and entirely self-sufficient, using solar panels or wind or water turbines to for energy, an electric engine and a water generator that turns salt water or rain into drinking water.
The vessel isn't for those who have a need for speed, as it would have a top speed of just three knots (3.45mph).
The designers behind the UFO project are the same ones who created the carbon fibre Jet Capsule, a concept vessel that they say can be used as a luxurious compact yacht, taxi, police cruiser or even a military patrol vehicle.
The team said the proportions have never been used before on watercraft and create a very spacious interior which can accommodate 13 people, including the operator, who can stand up or even dance without any problem.
The interior has a height of just under seven feet and it has heating and air conditioning to keep the occupants comfortable, regardless of the outside temperature.
A roof deck is accessible via stairs from the back of the vessel, which has a full carbon fibre body, private jet layout, rear doors, and tinted windows, and can come with a toilet and bed.
With an overall length of 7.55 metres (24.7ft), the Jet Capsule runs on a diesel or petrol engine and can hit a maximum speed of 32 knots (36.8mph), although faster models are available.