A method of installing a socket with a socket contact on an underwater plug with a plug contact is provided so as to establish conductive contact between the socket contact and the plug contact. The socket is disconnectably attached to a recoverable fluid exchange unit and the socket engages with the plug to establish the conductive contact between the socket contact and plug contact. The recoverable fluid exchange unit is then operated to substantially replace a first fluid within the socket with a second fluid from the recoverable fluid exchange unit.