A system to locate seismic data acquisition units in a marine environment, comprising: a first seismic data acquisition unit and a second seismic data acquisition unit, the first seismic data acquisition unit comprising: a case having a wall defining an internal compartment; a power source, a clock, a seismic data recorder, and at least one geophone disposed within the case; a ring of cleats positioned on a perimeter of a top side of the first seismic data acquisition unit to couple, in a stack, the first seismic data acquisition unit with the second seismic data acquisition unit ; characterized by a rope having a first end coupled to a first portion of the first seismic data acquisition unit and a second end coupled to a second portion of the first seismic data acquisition unit , the first end coupled to a first portion of the first seismic data acquisition unit within the perimeter formed by the ring of cleats , and the second end coupled to the second portion of the first seismic data acquisition unit within the perimeter formed by the ring of cleats forms a hoop configured to couple to an underwater vehicle during a fly-by deployment or a fly-by retrieval; a cavity formed by the ring of cleats on the top side of the first seismic data acquisition unit; a telltale component coupled to a portion of the rope; and the rope and the telltale component stored in the cavity of the first seismic data acquisition unit , wherein the second seismic data acquisition unit is coupled with the first seismic data acquisition unit via the ring of cleats on the perimeter of the top side to form the stack. a first seismic data acquisition unit and a second seismic data acquisition unit, the first seismic data acquisition unit comprising: a case having a wall defining an internal compartment; a power source, a clock, a seismic data recorder, and at least one geophone disposed within the case; a ring of cleats positioned on a perimeter of a top side of the first seismic data acquisition unit to couple, in a stack, the first seismic data a case having a wall defining an internal compartment; a power source, a clock, a seismic data recorder, and at least one geophone disposed within the case; a ring of cleats positioned on a perimeter of a top side of the first seismic data acquisition unit to couple, in a stack, the first seismic data acquisition unit with the second seismic data acquisition unit ; a rope having a first end coupled to a first portion of the first seismic data acquisition unit and a second end coupled to a second portion of the first seismic data acquisition unit , the first end coupled to a first portion of the first seismic data acquisition unit within the perimeter formed by the ring of cleats , and the second end coupled to the second portion of the first seismic data acquisition unit within the perimeter formed by the ring of cleats forms a hoop configured to couple to an underwater vehicle during a fly-by deployment or a fly-by retrieval; a cavity formed by the ring of cleats on the top side of the first seismic data acquisition unit; a telltale component coupled to a portion of the rope; and the rope and the telltale component stored in the cavity of the first seismic data acquisition unit , wherein the second seismic data acquisition unit is coupled with the first seismic data acquisition unit via the ring of cleats on the perimeter of the top side to form the stack. <EOS>