Localization underwater can be done through acoustics, optics, and magnetic induction. We use these technologies to estimate the position of devices deployed underwater at different error ranges. We consider both collaborative and non-collaborative sources for localizing objects. We confine ourselves to devices that reside in the boundaries, i.e., either on the surface or on the bottom of the ocean. The scope of the localization can be to: discover a device for collision avoidance or for mid-point navigation, localize and recover lost equipment, and finally, for optimal docking.