Vietnam hasn't given proper support for to local amateur inventors Minister of Science and Technology, Nguyen Quan, said.

Quan explained that many of these inventors had never sourced official support.

"Producing and operating submarines and aircraft must be registered with the Ministry of Defence," Quan said. "These inventions will not be allowed to put into use if their owners don’t register their works with relevant agencies."

Quan also said that Vietnam now has no regulations on using the state budget to support initiatives by members of the public.

"Therefore, we can only send experts to support them in their studies and design if they express a need," he said. "We can’t provide them with finance at present. But we have a draft circular on the issue and I hope amateur inventors will get financial support once it is passed.

Regarding intellectual property, Minister Quan reassured local inventors that their initiatives would be well protected if they follow the registration process.

Last year, Nguyen Bui Hien, a 61-year-old car engineer from Binh Duong Province completed his second helicopter and sought permission from the Ministry of Defence to conduct a test flight. Hien said the new helicopter was safer and more modern than his 2012 invention. It flies, takes off and lands smoothly.

Hien's stainless steel helicopter is 7.4 metres long, 2.4 metres high, weighing 340 kilos when empty. It was designed to carry a maximum weight of 500 kilos. It tops out at 200kph and can remain in the air for two hours, using common 92-octane petrol.

Hien says he was confident he would get a permit to conduct a test flight and prove his helicopter could be used in agriculture, surveying, filming and rescue.

A mini submarine built by a private engineering company in the northern province of Thai Binh has also captured the public’s imagination.

The submarine was designed and manufactured by Nguyen Quoc Hoa, director of the Quoc Hoa Engineering Company.

The 8.8 metres long and 3 metres wide submarine has been successfully tested twice last year.

Hoa, six other engineers and more than 30 workers began to build the submarine in August 2012.

Hoa told Tuoi Tre Newspaper that he wanted to create such a submarine simply to satisfy his passion for scientific exploration. After further tests, he wants to co-operate with local enterprises to produce submarines.