Abstract: The present invention describes an apparatus (1) for establishing a subsea environment to enable an intervention operation to be carried out on a pipe, the apparatus comprising a frame (2) adapted to abut an outer surface of the pipe, sealing means (7) to enable the frame to be sealed against the surface of a pipe, and means for monitoring the condition of the seal, wherein the environment is established between the frame and the surface of the pipe and further describes a method of establishing a subsea environment to enable an intervention operation to be carried out on a pipe, the method comprising the steps of deploying a frame (2) subsea, locating the frame against the side of a pipe to establish the environment between the frame and the pipe, sealing the frame against the side of the pipe, and monitoring the condition of the seal.