A method of heating an inner pipe of a set of coaxial pipes, wherein the inner pipe is heated by induction using an electromagnetic induction coil (5) surrounding the outer pipe coaxially, the coil passing electrical power at a frequency lower than 100 Hz optimized for maximum energy efficiency of Joule effect heating of the inner pipe. A device (8) is also provided for induction heating an inner pipe of coaxial pipes, the device has a) an induction heater having at least one electromagnetic induction coil (5) coaxially surrounding the outer pipe of the coaxial pipes, and b) a raising device (9) for raising a portion (1-2) of coaxial pipes (1) above the sea bed (13) together with the induction coil(s) (5) surrounding it.