Interisland travel could be cheaper, cleaner and lower under a proposal by a partnership between state agencies and a private transportation developer.

The Hawaii Seaglider Initiative is a coalition of local stakeholders advocating for the adoption of seagliders — a proposed electric- powered vehicle that flies low above the water — as an interisland transportation option.

The initiative announced Friday that three state agencies — the Office of Hawaiian Affairs, the Hawaii Community Development Authority and the Hawaii Center for Advanced Transportation Technologies — have joined the group.

Seagliders are a proposed vehicle by Rhode Island company REGENT Craft Inc., one of the partners of HSI. They are unconventional vehicles classified as “wing-in ground effect vehicles,” or WIGs, which use the ground effect — the interaction between a moving wing and a surface below — to reduce aerodynamic drag and generate lift while close to the surface, the ocean in this case.

HSI Co-administrator David Uchiyama said the seaglider is based on a Soviet aircraft design called the “ekranoplan,” which never reached widespread use.

The seaglider is a multiphase vehicle: It launches as a seaborne vessel before its velocity raises it up to glide on a hydrofoil, which then retracts once the vehicle reaches full speed.

Seagliders fly only about 30 to 60 feet above the ocean surface but are able to reach top speeds of about 180 miles per hour, Uchiyama said. Compared with conventional interisland flights, Uchiyama said this is “not much slower,” particularly when you take into account the need for airliners to ascend to full altitude and then descend.

A seaglider flight between islands could be only about 15 minutes longer than a conventional flight, while avoiding the need to go through airport security, Uchiyama said.

HSI’s proposal is for seagliders to launch and land at ports around the state — two ports for every island, Uchiyama said. The initiative has suggested that Kewalo Basin Harbor in Honolulu would be an ideal space to host the vehicles.

While the vehicles are still in the prototype phase — Uchiyama said he doesn’t expect REGENT to begin production until 2026 — several airlines have expressed interest in the technology. Hawaiian Airlines and Japan Airlines are listed as REGENT investors, and both of those also are HSI partners, as are Alaska, United, Southwest and Mokulele airlines.

Because the vehicles operate at about one-third the cost of a conventional aircraft, Uchiyama said they are envisioned as a cheaper alternative for residents to get between islands, and that “culture and community” is one of HSI’s core pillars.

The partnership with OHA, he said, is indicative of the proposal’s potential to help Hawaiian communities connect over long distances.

“Understanding the feasibility of offering seaglider transportation in Hawaii will provide new opportunities to empower Native Hawaiians and help them gain better access to health care and other essential needs,” said OHA CEO Stacy Kealohalani Ferreira in a statement.

In 2025, Uchiyama said, HSI will work with the state to pursue federal funding in an effort to launch a feasibility study that could lead to an environmental impact statement.

“Obviously, there’s a lot of ground to cover,” Uchiyama said, adding that the vehicles also need to pass federal certification requirements.

Currently, he said, REGENT is pursuing certification with the U.S. Coast Guard primarily but is also making inroads toward Federal Aviation Administration certification.

But, he added, other companies are likely to pursue similar technology in the future and that funding to enhance Hawaii’s ports — installing electrical charging infrastructure, among other things — will benefit the whole state in the long term.