Low-level noise propellers with a higher performance are required lower incipient cavitation number of tip vortex cavitation and even if tip vortex cavitation is developed, to depress the underwater noise level. In this study, the author provided some highly skewed propellers that were modified propeller geometry to influence low-noise performance and then the incipient cavitation numbers and the underwater noise were measured at a cavitation tunnel by using the propeller models. From the results, we found that the propeller with lower incipient cavitation number does not always have low-level underwater noise even if the cavitation is generated. Also the author shows a guideline in design of low-level noise propellers by referring to the results from the measurements and CFD analysis.