Abstract: A method for controlling subsea drilling operations including, in at least certain aspects, controlling the subsea drilling operations with a control system having three subsea pod containers of a control system, each with apparatus for controlling the subsea drilling operations, the system also having activation apparatus for activating a chosen one of the subsea pod containers and maintenance apparatus for maintaining the two subsea pod containers other than the chosen one in a standby mode providing triple redundancy of control of the subsea drilling operations.

Abstract: A method for controlling subsea drilling operations which, in at least certain aspects, includes controlling the subsea drilling operations with a control system having three subsea pod containers of a control system, each with apparatus for controlling the subsea drilling operations, the system also having activation apparatus for activating a chosen one of the subsea pod containers and maintenance apparatus for maintaining the two subsea pod containers other than the chosen one in a standby mode so that triple redundancy of control of the subsea drilling operations is provided, so that the subsea drilling operations are not interrupted during retrieval of a pod whose apparatus for controlling the subsea drilling operations has failed; and methods with such a system for retrieving a subsea pod from a lower marine riser package platform.

Abstract: A method for retrieving a subsea pod from a lower marine riser package platform by connecting a buoyant pod retriever to the subsea pod and raising the subsea pod to the surface. In certain aspects, such a method is accomplished without an interruption of associated subsea drilling operations and/or without disconnecting the lower marine riser package from an associated subsea stack. Such a method, in certain aspects, includes: positioning a retrieval module above the pod container, the retrieval module having a pod holder releasably connected thereto; disconnecting the pod holder from the retrieval module; lowering the pod holder to the pod container and releasably connecting the pod holder to the pod container; releasing the pod container from the subsea lower marine riser platform; raising the pod holder to the retrieval module and releasably connecting the pod holder with the pod container to the retrieval module; and raising the retrieval module with the pod container to a location at the surface.