Abstract: An energy generating unit especially for installation on a bed of a stream of water or floating in the water, composed of a plurality of components, such as an inlet housing, a turbine housing, a drive unit arranged in the turbine housing, and a downstream draft tube, in which at least one component is provided with remotely operable connectors and with guides so as to be separable from at least one other component while in the water such that the at least one component, such as the drive unit, can be removed from the water for maintenance while the at least one other component, such as the draft tube, remains in the water, as well as a method for maintaining such an energy generating unit by selectively removing at least one component from the water while at least one other component remains in the water.