The recent development of drones for very high altitudes or hybrid airships that generate aerodynamic lift in addition to the aerostatic lift typical of airships brought attention to the analysis and design of very low Reynolds number configurations. This work, in particular, focuses on the design issues of a propeller for this type of airship equipped with electric propulsion, which must offer high performance in terms of efficiency in the presence of phenomena such as the transition from laminar to turbulent flow and laminar bubbles. Dealing with these phenomena in the design phase is difficult because their correct prediction requires sophisticated and computationally expensive computational models. The approach followed here is hierarchical and is based on a hierarchy of solvers of increasing fidelity, moving from an integral boundary layer coupled to a potential solver with compressibility correction to approaches based on the coupling of solvers of the Euler or Reynolds Averaged Navier-Stokes equations (RANS) coupled boundary layer with simple transition models, up to RANS solvers with transitional turbulence models such as γ-Reθ. The adopted approach starts from the 2D multi-point design of various airfoils for different radial stations of the propeller blade, carried out with an evolutionary approach, and, in a second step, these profiles are used to design the propeller blade. The developed methodology is demonstrated in a challenging case study in which we will also try to evaluate the margins of uncertainty of the developed design.