Hawaii astronomy and marine cruise: US

May 2026 - 9 days

Register for 2026 now at tours@newscientist.com and we will contact you later this year with confirmed tour details.

A unique astronomy experience combining the beauty of the night sky with the serene setting of the ocean. Cruise around the beautiful and fascinating islands of Hawaii aboard a rugged expedition yacht – the Safari Explorer – that is small enough to venture where larger ships can’t. Visit Hawaii's world-famous observatories whilst discovering the islands unique marine life, culture and history. 

Begin on Hawaii's Big Island, which is home to some of the world's most advanced astronomical observatories, largely due to its geographic advantages. The state’s volcanic mountains, particularly Mauna Kea on the Big Island, provide high-altitude sites with stable atmospheric conditions ideal for observing the cosmos. Mauna Kea, standing 13,796 feet above sea level, offers astronomers clear skies, minimal light pollution, and low humidity, making it one of the best places for astronomical research.

From here, set sail and embark the Safari Explorer, accommodating 36 guests in 18 cabins. Join guided nature hikes ashore, snorkel among coral gardens and keep watch for whales, dolphins and other marine life from the deck. By cruising on a smaller vessel, you can enjoy a more flexible and intimate experience, travelling with like-minded fellow passengers in search of wildlife and natural wonders.

Hawaii’s geographic location allows for excellent visibility of both northern and southern hemisphere stars, providing a broader view of the night sky compared to other locations. In addition to stargazing, you will learn about Hawaiian navigational traditions, focusing on how ancient Polynesians used the stars to explore and settle vast areas of the Pacific Ocean. 

In partnership with Polar Routes. 

DAY 1: ARRIVE BIG ISLAND, MAUNA KEA OBSERVATORY VISIT AND STARGAZING

You will be met and transferred to the Marriott King Kamehameha's Kona Beach Hotel in Kailua-Kona for a day at leisure. Referred to both as "Kailua" and "Kona" by local people, it is where the Hualalai volcano meets the ocean. For an insight into Kona's interesting history, visit sites such as Hulihee Palace or Mokuaikaua Church.

In the late afternoon, meet in the hotel for a welcome meeting before travelling to the Mauna Kea Summit which stands at 13,796 feet above sea level, providing an unparalleled view of the sunset. Many tours take visitors up to the summit in the late afternoon to witness the sunset over the clouds, a spectacular sight that’s often described as otherworldly. You’ll also get the chance to view the massive observatories, including those from institutions like Keck and Subaru.

After the sunset, head down to a lower elevation (around 9,000 feet)  where you will enjoy dinner at a restaurant near the observatory. Afterwards, there will be a guided stargazing session. In addition, portable telescopes will be set up to allow you to observe planets, star clusters, nebulae, and distant galaxies. Mauna Kea’s remote location and high elevation offer some of the clearest and darkest skies on the planet.

DAY 2: BIG ISLAND OBSERVATORIES AND THEN BOARD THE YACHT

Depart your hotel at 08:00 to explore Big Island's observatories and astronomy centres. Hawaii’s observatories have played key roles in major discoveries. For example, the Keck Observatory helped identify planets orbiting distant stars and provided insights into the structure of our galaxy. Similarly, research on gravitational waves has benefited from these observatories' capabilities.

Return to Mauna Kea Visitor Information Station (VIS). It provides exhibits about the astronomy and geology of the area and offers information about the observatories near the summit. 

Continue the Imiloa Astronomy Centre located in Hilo. The centre has interactive exhibits about space science and the importance of Mauna Kea to both modern astronomy and ancient Polynesian navigation. It features a state-of-the-art planetarium where you can enjoy an immersive show about the stars and planets visible in the Hawaiian night sky.

Take lunch at Lava Rock Cafe, before travelling to Kawaihae Harbour, to embark your boat, the Safari Explorer. You will have time to settle in to your cabin before sitting down this evening to your first dinner aboard the yacht. The guides will give a presentation full of information about the week ahead.

DAY 3: BIG ISLAND

Explore Kealakekua Cove, known as a premier snorkeling and kayaking destination in the Hawaiian Islands, is also the historic site of the Cook Monument, marking where Captain Cook met his end in February 1779. Here, you can encounter vibrant marine life, including tropical fish, sea turtles, and possibly dolphins.

In the afternoon, we set off on a Marine Mammal Search, potentially taking us to the remote South Point area.

DAY 4: BIG ISLAND

This morning, you will take a rocky hike up the cool and misty slopes of Hualalai Volcano. Explore our private trail at 6,500 ft above the Kona coast with your own naturalist guide. Cross surreal scenes of black lava flows, pass pit craters and stroll through native dryland forest. You’ll discover a lava tube and learn how lava flows from the early 19th century reshaped the coastline below you. This evening you'll anchor at an offshore location to search for and night snorkel with Giant Pacific Manta rays. This award-winning excursion offers snorkelers the opportunity to observe these majestic animals up close and personal. Marine life is often within inches, offering a unique experience with wild animals in their environment. Strict guidelines are followed to lessen any disturbance of these beautiful creatures.

This evening, the Safari Explorer will anchor at an offshore location for a thrilling night-time snorkelling adventure with giant manta rays. The reef manta rays (Mobula alfredi) you should see here are the second largest species of manta rays in the world and can have a wingspan of 5.5 metres. The reef manta rays in Hawaii don't migrate and spend their lives in the coastal waters around the islands.

During the manta ray night snorkel, you will spend your time in the water holding onto a floating board. A bright light attached to this board shines down into the water, attracting plankton. The manta rays feed on this plankton and come very close to the water surface while feeding. It is a mesmerising experience.

DAY 5: MAUI

In ancient times, the community of Olowalu on the west of the island of Maui was known throughout the Hawaiian Islands as a place of sanctuary, however it also has a turbulent and poignant history. Today, the community of Olowalu is home to one of the most unique ocean reef systems in all the Hawaiian Islands, known locally as Turtle Reef. Snorkel in this sea turtle habitat among 100-year-old coral gardens that are swarming with an abundance of tropical marine life. Sail through the Humpback Whale National Marine Sanctuary, a designated expanse of shallow warm waters that surround the main Hawaiian Islands, and learn from the guides about one of the world's most important protected marine habitats. From the decks, search for humpback whales, spinner dolphins, Hawaiian monk seals and reef fish.

DAY 6: LANAI

Wake up to views of the tranquil island of Lanai, the smallest inhabited island in Hawaii, and prepare for a full day of water and land-based excursions. Enormous sea cliffs line the coastline and ancient volcanic plugs protrude above the surface of the ocean. You can explore these calm waters by floating atop the surf with a snorkel or by heading out on a paddle board or in a small boat. Ask the onboard guides about the offshore wreck of a second world war tanker that rests off the coast of Shipwreck Beach.

On land, hike to Puu Pehe (also known as Sweetheart Rock), an ocean rock formation steeped in folklore that rises majestically 25 metres out of the sea and towers above the crashing surf. Learn about the history of Lanai and its historical plantation days, when it produced 75 per cent of the world's pineapples. It will also be possible to visit the quaint Lanai Culture and Heritage Center to absorb the history and traditional culture of what is colloquially known as "Pineapple Island".

DAY 7: CAPTAIN'S CHOICE EXPLORATION

Today, the captain will navigate to a site that uncovers more of what the Hawaiian Islands have to offer. Dramatic volcanic backdrops, marine life sightings and opportunities to embark on kayak explorations are all possibilities.      

DAY 8: MOLOKAI

Spend the day on Molokai, meeting local people and learning about the traditions of the Hawaiian people. In the evening, enjoy one of Hawaii's cultural treasures, a pa'ina (feast) held at the Molokai Museum. Discover the history of this ancient homeland as you experience singing, dancing, traditional cuisine and Hawaiian decor.

DAY 9: DISEMBARK FOR YOUR HOMEWARD JOURNEY

You have the opportunity to add a tailor-made pre or post-sailing tour extension.