When a cannonball collides with sea water, the resulting impact force influences the cannonball trajectory, depending on launching angle, initial firing speed, incident angle, and cannonball nose-cone shape. In this study, the effect of nose-cone shape of a cannonball on impact and ricocheting behavior was investigated. During collision, the flow was assumed to be non viscous and incompressible, and a source panel method was used to determine velocity potential and pressure coefficient. The nose-cone shape was expressed by Haack-series. It was found that as the radius of curvature of a cannonball nose-cone decreases, a high impact force is resulted, and that depending on impact force and impulse, the ricocheting distance varies. The results obtained in this study can be used in researching and developing new cannonballs.