Spectacular floating hotels: Conrad Maldives' Sunset Water Villas are suspended on stilts over the Indian Ocean.
Infinity pool: Each of Rangali's 50 villas has an infinity pool. Even when you're indoors, you can view the water though a glass floor in the living area.
Underwater restaurant: There are only 12 seats at Conrad Maldives' Ithaa undersea restaurant, and all of them have equally fantastic views of the ocean overhead.
Taj Lake Palace: Taj Lake Palace in Udaipur, India, was used as a film location in the 1983 James Bond film "Octopussy."
Pleasure palace: Built in 1746 as a pleasure palace for Prince Maharana Jagat Singh II, the Taj Lake Palace has 66 rooms and 17 suites, all with views of the lake.
Manta Resort: Tanzania's Manta Resort has a watertight underwater room submerged four meters below the surface of the Indian Ocean.
Swedish design: Seven years in the making, the room was designed by Sweden's Genberg Underwater Hotels.
Good Hotel London: Good Hotel opened in London's Victoria Docks in late 2016, having traveled by barge from Amsterdam across the North Sea.
Good deeds: Good Hotel has a 10-month training program to help the long-term unemployed get back into work.
Salt & Sill: Sweden's Salt & Sill is found in the Bohuslan Archipelago of around 10,000 islands. Some rooms have their own ladder leading straight to the sea.
Swedish luxury: Salt & Sill's other big draw is its man-made lobster reef measuring around 40 square meters and a catamaran hosting a floating sauna.
Beach Villa Ocean Suites: Resorts World Sentosa's Beach Villa Ocean Suites are part-submerged along one side of Singapore's S.E.A. Aquarium.
Amenities: The Ocean Suites still come with all the amenities you'd expect from five-star luxury including Wi-Fi, 24-hour in-room dining and 24-hour personal butler services.
OFF Paris Seine: Moored near Austerlitz station, boat hotel OFF Paris Seine is 80 meters long and has 54 rooms.
Sunset Suite: Its Sunset Suite is a wash of orange from walls to soft furnishings. It's the work of trend forecaster Tal Lancman and haute couture designer Maurizio Galante.
Salt & Water catamarans: Serbian design studio Salt & Water are developing houseboat-style catamarans for use on inland water including lakes and rivers.
Choose your own adventure: Docked onto a central floating hotel with a reception and restaurant, each catamaran can be detached and navigated for a more private experience.
Solent Forts: Solent Forts, off England's south coast, began life as three man-made sea fortresses commissioned in the mid-19th century to see off a French invasion that never materialized.
Vacation island: Two of the three fortresses have been turned into private vacation islands with bedrooms, bars, restaurants, rooftop hot tubs and spas.