For tidal stream designers main challenge is that the design can sustain in hostile marine environment. Due to lift base design the vertical axis tidal turbine (VATT) is very critical for cavitation, so proper blade hydrofoil selection can improve the hydrodynamic performance and life of the turbine. An attempt to optimize the design parameters of VATT for various configurations is made. Geometrical Parameters like number of blades N, tip flow speed ratio λ, power coefficient CP, and turbine solidity ơ are focused in study. The aim is to optimize the design for better hydrodynamics performance and structural strength....