“I believe future submarines will be smaller, because of the use of more advanced technologies as well as the pursuit of more cost-effective production,” Sergei Sukhanov said in an exclusive interview with RIA Novosti.

“The fifth-generation boat will also be less ‘visible’ compared with existing submarines. They could also feature a new power plant, including fully electric,” Sukhanov said, adding that changes could affect other sub-systems of future submarines.

The designer said the most likely substitution for a nuclear reactor on strategic and attack submarines would be an air-independent propulsion plant (AIPP), which would make them stealthier than nuclear-powered boats.

The AIPP allows a non-nuclear submarine to operate without the need to access atmospheric oxygen.

While a nuclear submarine’s reactor must constantly pump coolant, generating some amount of detectable noise, non-nuclear boats running on battery power or AIPP can be practically “silent.”

“The endurance of submarines with this type of propulsion should be sufficient [for patrol or strike missions] – for a month or even more,” Sukhanov said.

He said the construction of fifth-generation submarines in Russia could start in the next 10 to 15 years.

The Russian Navy currently relies on third-generation submarines, with fourth-generation subs of the Project 955 Borey class of strategic boats and Project 885 Yasen class of attack boats just beginning to be adopted for service.