Hainan's negative list for foreign investment is the shortest in the country, Feng said, extending a warm welcome to international investors.

Sean Stein, president of the US-China Business Council, offered a concrete example of how Hainan's new policies are changing investment decisions. "Previously, a major US company that refurbishes used products from Southeast Asia and Japan could not do so in China due to regulations. Now, after the kickoff of island-wide special customs operations, the company is setting up a base in Hainan to renovate and re-export the products globally," Stein said. "That's a big, encouraging change."

Tesla has also seen a surge in activity across its Hainan outlets. A Tesla spokesperson told China Daily that Hainan's ecological advantages and open policy environment make it "an ideal base for promoting green mobility worldwide". Due to the new customs policies and local government subsidies, foot traffic at Tesla's stores in Haikou has risen 20 percent month-on-month.

The influx of foreign businesses is not accidental. Hainan has been systematically improving its business environment. Chen Shuying, an official of the Hainan provincial market supervision administration, said that a series of reform measures have shortened the preparation time for foreign-funded enterprises to invest in Hainan.

The process for foreign enterprises has been changed from "separate handling by different departments" to "integrated processing", compressing the number of procedures from five to one and reducing paperwork by more than 77 percent, Chen said.

In late April, Hainan issued a three-year action plan to improve foreign-related services and the international business environment, introducing 30 specific measures in seven areas. These include extending Hainan's enterprise registration window to Hong Kong and offering customized "one enterprise, one policy" services for key industries.

He Jifeng, deputy director of the Hainan Provincial Department of Business Environment Development, said the action plan aims to create a precise foreign investment service system covering the entire lifecycle of enterprises.

"We will refine annual plans, clarify timelines, strengthen coordinated implementation and put every reform measure and every service scenario into practice — so that more foreign enterprises can invest with confidence, operate with ease and develop with focus in Hainan," said He.

For Heilig, Hainan's progress is still in the early stages, but he is optimistic. "We are watching closely. For German companies, our needs include not only open policies, but also important international infrastructure — education, medical resources and most importantly talent to support business development," he said. "Much work is being done. We believe Hainan will develop well."

When asked whether Hainan could become a new center or model for China-Germany cooperation, Heilig did not hesitate. "I hold a very positive attitude. I believe it will certainly become a new model or benchmark."

That confidence is shared by many. Burnett from the China-Britain Business Council, after a beach walk at sunset, put it simply: "You sometimes forget that you're in an industrial zone. So you can come to work, invest in Hainan and feel like you're on holiday."

Behind that pleasant feeling lies a serious business case. With its unique policies, improving infrastructure, coordinated governance and growing openness, Hainan is steadily transforming from a tropical resort into a genuine hub for global investment, experts said.

Contact the writers at masi@chinadaily.com.cn