SS Montebello SS " Montebello " was an oil tanker sunk by the Japanese submarine , I - 21 , off the coast of California on December 23 , 1941 . Ship description . SS " Montebello " was a shelter - deck oil tanker built by the Southwestern Shipbuilding Company in San Pedro , California for the Union Oil Company . She was launched in 1921 . Steel hulled , she had a length of , beam of , and draft of . The ship had ten divided liquid storage tanks which ran the width of the ship and was a single - hull design . She had an expected life of 25 years and was 20 years old when torpedoed . When she went down , " Montebello " held of crude oil along with of fuel oil for her engines . Sinking . " Montebello " was torpedo ed after leaving for Vancouver , British Columbia , from the small Central Coast seaport of Port San Luis . The officers and crew were aware there had been several attacks on American shipping off the West Coast . The risk was so high that " Montebello " s skipper had refused to take the ship to sea and he quit . After replacing the captain with the chief mate , Olaf Eckstrom , they set off at midnight . By 5 : 45 am , off the coast of the small town of Cayucos , California , just north of Morro Bay , two torpedoes hit the ship , though one was a dud . The torpedo responsible for the sinking struck forward in the pump room and dry storage cargo hold . The crew was unarmed , and as the men jumped into lifeboats , the submarine surfaced and fired at them with its deck gun . By 6 : 30 am , the ship had stood on her bow and slid under , according to a report published the next day . No one was killed . Exploration of the wreck . In an expedition conducted on November 7 , 1996 , the submersible " Delta " descended with two men on board to the wreck at a depth of and found " Montebello " sitting upright on the bottom . Based on their observations it was concluded that a single torpedo hit " Montebello " just forward of the pump room . While the bow was broken from the impact with the sea floor , the overall condition of the wreck was thought to be quite good , giving rise to the concern that she may still hold her liquid cargo . In August 2010 the wreck was examined by a robot submarine from the Monterey Bay Aquarium Research Institute to determine whether the oil cargo was still on board and whether it posed a possible environmental threat . The expedition created three - dimension images of the ship using sonar , which are being analyzed onshore . Jack Hunter , an archaeologist for Caltrans who examined the wreck in 1996 and compared the images from the 2010 expedition expressed concern that the wreck has deteriorated over the past 14 years and could represent a risk if the cargo leaks . Further explorations of the wreck were scheduled for 2011 . The expedition is expected to cost $ 2 . 3 million , to be paid for out of a fund which oil companies pay into for such situations . A report on a recommended course of action is expected to be released late 2011 . After two weeks of extensive testing in October 2011 , researchers determined that no crude oil remained in the tanker and such oil most likely was released from the vessel shortly after sinking and dissipated throughout the region .