Abstract
When the two ships of the same type are rolling in regular waves with the phase difference of ε, the amplitude of |Δθ| of the relative rolling angle between both ships is expressed by |Δθ/θ|=2|sinε/2| derived from the equation of rolling. In this case, |θ| represents the amplitude of rolling angle of the ship in regular waves. Utilizing the above equation, the present writer discusses in this paper the phase difference on the optimum distance between both ships in rescue operation.
