Abstract. A methodology to optimize the design of an offshore tsunami network array is presented, allowing placement of sensors to be used in a Early Tsunami Warning System framework. The method improves on previous methods by including multiple tsunami parameters as a measure of the predictive accuracy through a single cost function. The use of different tsunami parameters allows for a network which is less subject to biases found when using a single parameter. The resulting network performance was tested against an historical event, suggesting that having such a network in place could have provided meaningful information for the hazard assessment. The low number of sensors required may be useful in implementing such networks in places where funding of denser arrays might be of concern.