A retrieval system and methods of preparing and using same to retrieve underwater objects from a selected depth, including a flotation device having at least a selected amount of buoyancy, a release mechanism that is capable of releasably engaging an anchor, and a controller to actuate the release mechanism when a selected condition is achieved. The system further includes a spool assembly having a frame for carrying (i) the floatation device, (ii) the release mechanism, (iii) the controller and (iv) in combination with the flotation device, a quantity of pre-wound line having a length greater than the selected depth.