The Poseidon Underwater Resort currently being developed 40ft below the ocean's surface off a remote private island in Fiji will eventually become the world's first sea floor five-star resort complex. The resort is about a mile long, spanning nearly 225 acres, surrounded by a 5,000-acre lagoon, and is accessible by a 16-passenger Triton luxury submarine. The project has been in the making for 13 years and is in the final stages of design by U.S. Submarines.
The resort will feature 24 undersea suites measuring 10m x 5.1m (33ft x 17ft) each, constructed as individual detachable modules coupled to the main corridor assembly. A high-tech carbon fibre outbound door is fitted to each suite that keeps the unit watertight during installation or removal, while a similar opposing door is fitted the main corridor to insure the complex's integrity. Closing both doors and flooding the space between results in the release of the module.
Nearly 70% of the suite's surface is made from strong and highly transparent acrylic plastic panels, which provide breathtaking view of the pristine ocean and coral garden. Other features of the resort include an underwater restaurant, a bar, a library, conference room, a fitness centre, a wedding chapel and spa.
Water Discus Hotel, Dubai
The Water Discus underwater hotel, under construction in Dubai, comprises two discs, one below water and one above water, connected by a vertical shaft containing a lift and stairway.
Located 10m beneath the ocean surface, the 1,000m2 underwater hotel is surrounded by coral reefs. It will feature 21 rooms, an underwater dive centre and a bar. The discus above water comprises swimming pools, sun deck, spa, restaurants and a helipad.
Polish firm Deep Ocean Technology designed the unique hotel, while Dubai-based Drydock World is constructing the project.
Apeiron Island Hotel, Dubai
The futuristic Apeiron Island Hotel in Dubai designed by Sybarite Architects is still in the conceptual stage. Located 300m off the coast of Dubai, the 7-star luxury hotel will be built on a man-made island and feature 438 suites occupying 28 floors.
The bottommost underwater floors will house a spa, gym and restaurant with views of tropical fish and colourful coral.
An underwater lagoon will allow guests to swim among the coral and fish. The hotel can be reached by helicopter or boat from the shore. Other features include private beaches, an art gallery, shops, cinemas, boutiques and nightclubs.
The Manta Resort, Pemba Island, Zanzibar
A private floating island, Manta Resort is situated 250m from the shore of the pristine Pemba Island, Zanzibar, off the coast of Tanzania. The underwater room lies four meters below the ocean surface and provides a 360º view of the crystal clear waters and aquatic life of the Indian Ocean.
The landing deck has a dining area and bathroom at sea level. The top deck has a lounging area for sunbathing and stargazing while the underwater room comprises the bedroom.
The room is designed by the Genberg Underwater Hotels Company, which was formed in 2006 following the success of the Utter Inn underwater accommodation in a private island. It is owned by Genberg Art UW and is operated by The Manta Resort.
Jules' Undersea Lodge, Florida, USA
Jules' Undersea Lodge, located in Key Largo, Florida, is the world's oldest underwater hotel and the only underwater hotel in the US. Named after Jules Verne, the author of 20,000 Leagues Under the Sea', the hotel is situated 20ft under water and balanced on the ocean floor by 5ft tall legs.
The hotel was originally developed in the 1970's as a research centre called the La Chalupa Research Laboratory, off the coast of Puerto Rico by research aquanauts Neil Monney and Ian Koblick. It was relocated to the coral reef in Florida and opened to the public in 1986.
The air-conditioned hotel comprises two private bed rooms and a common room.
Atlantis, The Palm, Dubai
Atlantis, The Palm is located on the world's biggest manmade island, The Palm Island in Dubai. The hotel includes two underwater luxury suites named Neptune and Poseidon that stretch over three levels.
The floor-to-ceiling windows of the master bedroom and bathroom in the suites look directly into the Ambassador Lagoon, a 10m-deep marine habitat housing 65,000 marine animals including reef fish, sharks and rays. The suites provide easy access to the underwater Lost Chambers aquarium and the 42-acre Aquaventure water park.
The resort also features a fine dining restaurant called Ossiano where guests can dine in a space surrounded by the aquatic life in the Ambassador Lagoon Aquarium. The WATG-designed Palm is accessed by a six-lane underwater vehicle tunnel that opens next to the resort.
Shimao Wonderland, China
The 5-star Shimao Wonderland Intercontinental Hotel is being built at the side of a 100m-deep abandoned water-filled quarry at the base of the Tianmenshan Mountain in China's Songjiang District.
Designed by British architecture firm Atkins and developed by the Shanghai Shimao Wonderland Property Group, the 19-story hotel will offer activities including water sports, rock climbing and bungee jumping. One level of the hotel is underground and features a restaurant and guest rooms facing a 10m deep natural aquarium.
The hotel is scheduled to be opened in 2015 and will be operated by InterContinental Hotels Group.
Conrad Hilton, Maldives
The Conrad Maldives Rangali Island resort in the Maldives opened the world's first undersea restaurant, the Ithaa Undersea Restaurant, in 2005.
Designed by New Zealand-based design consultancy M.J. Murphy, the 12-seat restaurant lies 16ft below the surface of the Indian Ocean. Its arched glass ceiling provides diners 180º view of the surrounding coral gardens.
The restaurant can be transformed into an underwater chapel for wedding. To celebrate the restaurant's fifth anniversary, the hotel offered to convert the restaurant into an exclusive suite for two.
Utter Inn, Sweden
The Utter Inn (or Otter Inn in English) is a single underwater room located in Västerås, Sweden. The private accommodation, opened in 2000, is designed by Swedish artist and sculptor Mikael Genberg.
The 80ft2 room lies 10ft below the surface of Lake Mälaren and is accessed by a boat. The hotel looks like a traditional, red Swedish house floating on the water's surface.
A ladder leads to the underwater room equipped with two twin beds, a table, a bathroom, and a camping stove.
Hydropolis is an underwater hotel being constructed 20m (66 feet) below the surface of the Persian Gulf, just off the Jumeirah Beach coastline in Dubai. Designed by Joachim Hauser and Prof. Roland Dieterle, the luxury hotel is set to be the world's deepest underwater hotel upon completion.
The project is being developed by Crescent Hydropolis Holdings on a 260ha land that belongs to Sheikh Mohammed Bin Rashid Al Maktoum, the Crown Prince of Dubai.
The hotel complex will comprise a wave-shaped land station to receive guests and a transparent Connecting Train Tunnel to transport guests to the undersea Submarine Leisure Complex. The jellyfish-shaped underwater leisure complex, the third part of the complex, will include 220 bubble-shaped suites as well as restaurants and entertainment facilities. Two translucent bubble domes above the water's surface represent the concert auditorium and a ballroom with retractable petal-like roof.