AChebyshevfittingwayforapropelleratlasacrossfourquadrantsisdiscussed.Asanexample,Chebyshevpolynomialfittingresultsanditserroranalysisaregiven.Becauseit’sdifficultgenerallytogetapropelleratlasacrossfourquadrants,awayisusedtoconstructanalternativewithhigheraccuracybasedontheproperties.Asanapplicationexample,analternativeforthepropellerpropertyofaDeepSubmergenceVebicleacrossfourquadrantsisgivenpracticallyandasimulationmodelofthe