A method, system and a marine node for recording seismic waves underwater. The node includes a first module configured to house a seismic sensor; bottom and top plates attached to the first module; a second module removably attached to the first module and configured to slide between the bottom and top plates, the second module including a first battery and a data storage device; and a third module removably attached to the first module and configured to slide between the bottom and top plates, the third module including a second battery.