The departure began with a final moment of silence. Twenty-nine crew members huddled on a canoe deck much like those used by their ancestors and considered the epic journey ahead, as several hundred onlookers watched in hushed anticipation from the shore.

Then, after nearly a week’s wait in Hilo for optimal winds, Hoku­le‘a, Hawaii’s "Star of Gladness," slipped out of Pale­kai’s placid waters and into a new frontier. The storied double-hulled voyaging canoe left Hawaii shores at 1:45 p.m. Friday afternoon for the open sea, destined for Tahiti and what ultimately aims to be a historic, three-year odyssey of aloha around the world.

In the next 36 months or so, Hoku­le‘a and her escort canoe, Hikianalia, are expected to sail more than 50,000 miles across three oceans, leaving the Pacific for the first time in Hoku­le‘a’s 39-year history.

The canoes and their crews will venture into unfamiliar and potentially dangerous waters to export a message of Malama Honua ("Care for Our Earth"). After the canoes enter the Indian Ocean, likely in August 2015 based on the current sail plan, crews will brace for churning, unpredictable seas off South Africa as well as threats of piracy and ship collisions off the East African coast.

Nonetheless, Polynesian Voyaging Society President Nai­noa Thompson and organizers of the Malama Honua voyage say the journey’s purpose is worth the risk they face. The canoes and their crews aim to deliver what they see as an urgent message of aloha and cultural harmony to the about 85 ports and 26 countries they plan to visit in the coming years.

They further look to rally people across "island Earth" around the 21st-century problems of vanishing natural resources, rising seas and changing climates. Crew members also hope the voyage will inspire Hawaiians to use the islands to pursue solutions.

The three-year voyage will likely involve more than 300 individual sailors on some 25 legs. If all goes as planned, the two wa‘a won’t return to Hawaii shores until 2017.

Hokule‘a and Hikianalia left Sand Island on Oahu on May 17 for Hilo. Crews on the voyage’s first international leg, to Tahiti, expected to leave about a week later.

However, a "really unusual weather pattern" akin to those typically found in winter kept the boats’ captains waiting until Friday for the conditions they would need to sail well east of Hawaii island, on a course that will eventually shift south en route to Tahiti.

Crews used the added days as a chance to recharge, guard their health and reflect on the undertaking ahead after a dizzying several weeks of public events and extended goodbyes. They stayed kapu, not meeting visitors, in the days leading up to Friday’s departure.

Malama Honua’s Tahiti leg is expected to take some 15 to 30 days. To make landfall, the canoes’ 29 crew members will rely on traditional means of navigation their Polynesian ancestors once employed, using the stars, waves and other natural cues to guide them. Thompson, a "pwo" (master) navigator and the first Hawaiian to revive the technique when he guided Hoku­le‘a to Tahiti in 1980, will again serve as captain and navigator aboard Hoku­le‘a on the leg.

By design many of the voyage’s crew members are under 30 years old, and several will train apprentice navigators on both canoes. One of the voyage’s goals is to season a new generation of leaders who can guide Hoku­le‘a into the coming decades.

"These young guys, they blindly will go if they’re asked by their older guys. But the journey for them began a long time ago when they committed to go, and they’re going to be very different people when they come home," Thompson said last week at Pale­kai in Hilo as the crew and canoes prepared to go kapu. "They’ll be children of the earth, and they’re going to be our leadership for tomorrow."