To address the issue of traditional buoys drifting significantly and losing navigational accuracy in strong currents in rivers and coastal areas,a study is conducted on reducing buoy offset by utilizing the combined effects of hydrodynamic lift generated by an underwater lifting body float and tension forces from a taut anchor chain.A numerical simulation method is employed to analyze the lift and drag characteristics of four NACA airfoil types:NACA 0012,NACA 0015,NACA 2412,and NACA 2415.Based on the analysis results,the NACA 2412 is selected as the baseline airfoil for constructing the underwater lifting body.A three-dimensional underwater lifting body is constructed by modifying this airfoil,and its lift and drag characteristics are subsequently analyzed to obtain a viable design for an underwater lifting body float.Numerical simulations and physical model experiments are applied to analyze the variation of buoy offset with flow velocity for a buoy model equipped with an underwater lifting body float,as well as for a series of buoy models using cylindrical float of the same volume.The results show that under equivalent flow velocity conditions above 2.5 m/s,the buoy equipped with an underwater lifting body buoy exhibited a 25% reduction in offset and a 58% decrease in maximum mooring cable tension compared with the cylindrical float buoy.Additionally,attitude stability is improved.The underwater lifting body buoy can meet the requirements of low offset and high navigation accuracy in strong current environments.However,the overall design must avoid negative angle of attack conditions for underwater lifting body.