An endless track belt for a submersible, autonomous vehicle is disclosed. The track belt includes an outer surface with raised track elements that are configured to both engage a supporting surface and selectively receive external grip elements configured to engage the supporting surface. The track belt also includes an inner surface with continuous, annular ridges. The continuous ridges are configured to secure the endless track belt to a drive pulley in a manner that prevents lateral movement while allowing for some longitudinal slip during rotational movement of the belt.