In this paper, two bidirectional three-phase dual active modular multilevel dc-dc converters are proposed for naval applications. In the first topology, two active modular multilevel converter are connected with a high frequency transformer. In the second structure, the front end is replaced with full-bridge modules involving modular multilevel converters and a three-leg inverter. Medium-voltage silicon carbide MOSFETs are used due to their high operating frequency leading to lower passive component size and weight. A commercially available 1.7kV SiC MOSFET is selected for this application. In the three-leg inverter stage, silicon IGBTs are used. A comparison is carried out between two proposed structures in terms of number of components, converter rating and efficiency using simulations in PLECS.