The narrative in “Jaws”, while entertaining, is not all that factual.

While it is true that the USS Indianapolis (CA-35) was under “secret” orders from its cruise from Mare Island to Pearl Harbour to Tinian Island, one has to remember that many ships during WWII were traveling under secret orders. Traveling under secret orders does not mean that the ship is isolated from the normal Movement Report System in place during WWII. While the cargo and its mission may have been handled very secretively, the actual transit of CA-35 was probably under the usual OPSEC procedures.

This being said, one has to remember that CA-35 was sunk not after delivering the components to Tinian Island, but was sunk after leaving Guam enroute to Leyte. So any “secret orders” that would have concealed the transit of CA-35 with respect to the nuclear weapons, would have ended. She completed her mission to Tinian; had traveled to Guam for a crew change and was now on a new, non-nuclear mission. As such, CA-35 was traveling under the same Movement Report System as other warships in that area.

So the story told in “Jaws” about no one knowing that CA-35 has sunk because of any security concerning the nuclear weapons is not true.

The true story about why no one knew about the sinking of CA-35 was a lot simpler and more tragic.

During WWII, the Movement Report System was used to monitor ships in transit. For CA-35 there were two such Movement Report Systems. The first was on Guam, the second was in the Philippines. Under normal circumstances CA-35 would be “checked out” of Guam when she left and “checked in” when arriving in the Philippine area. These statuses were transmitted to both stations. If a ship “checked out” of one port and failed to “check in” to the new port, an investigation ensued to find the ship. If this system were used properly, it would provide a double layer of security. In the case of CA-35, mistakes by different people were made.

1. CA-35 was checked out of Guam and after the anticipated transit time, the Guam operator, breaking procedure, removed CA-35 from the list, assuming that it had safely arrived.

2. CA-35 was checked into the Philippine area without verifying that she actually arrived.

This meant that according to both operating boards, CA-35 was safe and not missing, when in fact she was in the middle of ocean sunk. If the Guam and Philippine Movement Report Systems had followed procedures, CA-35 would have been “missed” sooner.

Additionally, there were tragic, and in my opinion, criminal mistakes made by radio receiving stations that received the distress signals from CA-35. According to declassified reports, CA-35’s distress signal was received by three US radio stations, but none of them reported the distress signal.

It appears that the tragedy of CA-35 was caused by a series of mistakes (many in my opinion criminal).

But one thing is for sure, the secrecy behind delivering the nuclear components from Mare Island to Tinian Island was not a factor.

A very interesting but at the same time sad incident.