Unlike a conventional jet engine that uses a rotating compressor to compress air into the engine for combustion , this one has no moving parts.

The main shaft between the air compressor and the gas turbine in a jet aircraft engine is hollow to permit an internal speed reduction shaft with the minimum requirement of space and weight.

There's no reason why the compressor and turbine blades in a jet engine can't be driven by an electric motor to generate thrust under water, he says.