Alila Purnama, Indonesia
This 46-metre mahogany vessel was built to resemble a traditional Indonesian phinisi sailing ship. The boat rises through three decks, with custom-made furniture in five cabins, a Padi-certified dive centre and several spaces for alfresco dining. Tailor-made charters around Indonesia are available year-round, but she also sails on set itineraries to wildlife-rich Komodo Island, the volcanic fleck of Ambon and the exotic chain of Raja Ampat in West Papua province.
Alila Purnama, Indonesia (01932 220908; alilahotels.com). Weekly charter from US$54,000 (£36,000), all inclusive. Sleeps 10.
Soneva In Aqua, Maldives
The Soneva Group will launch this luxury boat in January, offering offshore entertainment around the Maldives archipelago. The yacht will act as a waterborne offshoot to the group's five-star resort Soneva Fushi, with tailor-made itineraries and hotel-standard facilities including an on-board chef, dive instructor and spa therapist. The two luxurious cabins will include a master suite with sunken glass Jacuzzi.
Soneva In Aqua, the Maldives (00 960 660 0304; soneva.com). Nightly charter starts at US$5,375 (£3,583), full board. Sleeps four.
Silver Galápagos, Galápagos
Silversea's new ship starts sailing around the Galápagos Islands from September. Weekly departures will make a round-trip from Baltra Island, with a choice of two itineraries: North Central or Western. Both will take in endemic wildlife such as iguanas and grand tortoises, with stops at intriguing outposts such as Wizard Hill (a beach on San Cristóbal), Post Office (a bay on Floreana) and Frigatebird Hill (named after the red-pouched avians).
Silver Galápagos, Galápagos (0844 251 0837; silversea.com). Weekly itineraries start at £3,550 per person, all inclusive.
Aria Peruvian, Amazon
Aria is the newest of two Aqua Expeditions ships to sail the Peruvian Amazon. The 32-berth boat makes a round-trip from the jungle capital of Iquitos throughout the year, stopping on the banks to visit manatee rescue centres, go piranha fishing or glimpse macaws feeding at sunset. Relax back on the boat after excursions with gourmet cuisine in the restaurant, lectures in the bar or a chilled pisco sour on the deck.
Aria, Peruvian Amazon (00 51 1 434 5544; aquaexpeditions.com). Three-night itineraries start at US$2,835 (£1,890) per person, all inclusive.
Zambezi Queen, Botswana
The Zambezi Queen departs year-round for floating safaris along the Chobe River. Facilities on board include a library where you can read up on African wildlife, three sundecks and a pool for scoping out the real thing, and a computerised telescope to help you identify constellations in the African night sky. Each of the 14 suites comes with private balconies and huge windows for watching hippos and crocodiles outside.
Zambezi Queen, Botswana (00 27 21 715 2412; zambeziqueen.com). Two-night itineraries start at R8,000 (£573) per person, all inclusive.
Orient-Express is branching out in Burma. The group's new Ocaella boat will start cruising from July, adding to an existing hotel, the Governor's Residence, and a sister ship, The Road to Mandalay. With a range of itineraries along the Irrawaddy and Chindwin rivers, the elegant four-deck cruiser will feature 25 river-facing cabins, an observation deck and swimming pool. Visits will include the former capital Yangon, the temples of Bagan and the northern city of Bhamo.
Ocaella, Burma (0845 217 0799; orient-express.com). Weekly itineraries start at £3,270 per person, all inclusive.