Underwater camera enclosure including sonar range finding device

A system enabling the underwater utilization of an apparatus having an air distance measuring device normally operable to measure a distance to a subject in air and providing an initiate signal, said system comprising:

• a watertight enclosure retaining said air distance measuring device;
• an underwater ranging means receiving said initiate signal transmitting an underwater acoustic signal and receiving an underwater echo signal from an underwater subject;
• and
• means responsive to said received underwater echo signal for transmitting a detected echo signal to said air distance measuring device to provide a range signal therein corresponding to the distance underwater between said apparatus and said underwater subject.

A system enabling the underwater utilization of an apparatus having an air distance measuring device normally operable to measure a distance to a subject in air and providing an air-sonar acoustic signal, said system comprising:

• a watertight enclosure retaining said air distance measuring device;
• an underwater ranging means receiving said air-sonar acoustic signal transmitting an underwater acoustic signal and receiving an underwater echo signal from an underwater subject;
• and
• means responsive to said received underwater echo signal for transmitting a simulated echo signal to said air distance measuring device to provide a range signal therein corresponding to the distance underwater between said apparatus and said underwater subject.

A transponder to operate distance controlled apparatus designed for operation in a first medium, in a second medium and to provide a distance-related signal to adjust said distance controlled apparatus according to a distance between said controlled apparatus and a selected subject in said second medium, said transponder comprising:

• a second medium range determining device including a sonar device providing a first signal relating a distance between said transponder and said selected subject;
• a conversion means to relate said first signal to said distance controlled apparatus as a converted distance signal,
• wherein said second medium sonar device receives an initiate signal in response to said distance controlled apparatus and produces said first signal thereafter, said conversion means further comprising:
• a timing circuit to measure the elapsed time between said initiate signal and said first signal to produce a second medium delay signal;
• and
• a time scaler to adjust the second medium delay signal according to a differing rate of propagation of an acoustic signal through the first medium and the propagation of an acoustic signal through said second medium producing a simulated air-echo electrical signal.