Releasable guide post mount and method for recovering guide posts by remote operations

In a guide system for an underwater well installation of the type comprising a base secured to an upstanding well member and at least one guideline to be secured to the base and to extend from the base to the surface of the body of water, the combination comprising:

• a receptacle rigidly secured to the base and having an upwardly opening cavity;
• a guide post having a lower end portion of shape and dimensions to be accommodated by said cavity, said lower end portion having an outwardly opening locking recess;
• at least one locking element carried by said receptacle and movable between a first, inactive position, in which the locking element is disengaged from said locking recess when said lower end portion of the guide post is disposed in said cavity, and a second, active position, in which the locking element engages said locking recess to lock the guide post to the receptacle;
• and
• a movable operating member carried by said receptacle and movable between a first position, in which the operating member holds said locking element in its active position, and a second position, in which the movable operating member at least frees said locking element for movement to its inactive position, said operating member having externally exposed means for direct engagement by a remotely lowered and remotely operated tool.