Marine wave energy is a promising renewable source of energy in the world since it is characterized by high power density and worldwide distribution. Alternative to the well know permanent magnet linear synchronous machine and linear induction machine, a high power density tubular linear switch reluctance machine (TLSRM) is presented in this paper as direct drive marine wave energy generator. The translator of the machine consists of series of ring segments and there is only one set of round concentric winding in each stator slot, which significantly reduces the end of winding and manufacturing cost. It has been revealed that the presented machine exhibits high power density and low cost, thereby, to be a potential candidate for marine wave generator. Numerical optimization is used to determine the key dimensions which affect the machine performance. The performance of the presented machine are evaluated and compared with the traditional teeth type linear reluctance machine, validating that the presented machine shows significant advantages as marine wave energy generator.