Fig. 1. Foam-irregular-sea-surface hybrid model

Fig. 2. Structure of foam particle

Fig. 3. Schematic of beam transmission on foam-irregular-sea-surface

Fig. 4. Schematic of beam transmission on irregular sea surface

Fig. 5. Photon depolarization ratio versus scattering coefficient under different foam layer thicknesses. (a) Horizontal linear polarization; (b) 45° linear polarization

Fig. 6. Photon fidelity versus scattering coefficient under different foam layer thicknesses. (a) Horizontal linear polarization; (b) 45° linear polarization

Fig. 7. Polarization error rate versus incident angle under different foam layer thicknesses

Fig. 8. QBER versus transmission distance under different wind speeds

Fig. 9. Key generation rate versus transmission distance under different foam layer thicknesses