The fishfinder 320C is great for fresh or saltwater applications!. The Fishfinder 320C comes compatible with Garmins line of dual and single frequency transducers. The unit includes powerful features such as Bottom Lock which maintains a constant view within a specified depth of the bottom and water temperature recording with graph including Garmins exclusive depth control gain, which adjusts sounder sensitivity by depth, resulting in a more detailed picture of bottom structure. The Dual frequency transducer transmit power is 500 watts (RMS) and 4000 watts peak to peak. Displays depth up to 1500 feet!