In the Palomares incident of 17 January 1966 , a hydrogen bomb was lost in the Mediterranean Sea when a B-52 bomber collided with a KC-135 tanker near Palomares , Spain . The bomb was located , at a depth of , by the United States Navy submersible DSV '' Alvin '' after a 2 ½ month search . After '' Alvin '' was unsuccessful in recovering the bomb , the Navy brought in CURV-I . CURV-I was successful in attaching grapnels to the bomb but became entangled in the bomb ’s parachute lines . The entangled bomb , parachute , and CURV-I were successfully raised together to the surface 81 days after the original incident
Palomares incident
1966 Palomares B-52 crash
CURV