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On looking back at my wartime experiences in Pacific Fleet submarines in world War II, I have concluded that inadequate emphasis was placed on providing commanding officers with intelligence information.  Although  the  most  important  need  of commanding officer was where to find targets, there were other pieces of information that would also have proven useful.Among these were the locations of air bases, the ability of previous submarines to run on the surface in an assigned patrol area during daylight without undue Japanese interference, and, in view of the propensity of the enemy merchant ships to skirting the shores, how close had they approached the beach?, etc.

Looking back, I realize that neither COMSUBPAC nor any intelligence organization provided much information to submarines prior to departure on  patrol. Perhaps  they didn’t have much to give. In any case, CO’s were sent into assigned patrol areas and told to find their own targets as best they could. Other types of information on conditions in their assigned patrol areas were similarly neglected. For example, prior to departure on patrol, I was never shown a chart of my assigned area showing where earlier area occupants bad made contacts or attacked ships. Nor was I ever shown a chart of actual or expected Jap shipping lanes, despite the faot that such lanes existed and were vital to the economy of the resource-starved Japanese Empire.

Another example of our lack of intelligence information pertains to the Japanese use of radar. never saw  a  chart  of  enemy   radar Yet,radar signal intercept equipment was installed in our submarines as early as 1943. Our ECH equipment consisted of five or six separate and manually scanned tuning heads. But, due to the difficulty of searching the entire spectrum with the separate tuning heads, and the lack of information on enemy frequencies, it is doubtful that submarine ECM equipment was ever successfully used to detect approaching radar-equipped aircraft or ships. Twice bombed by Jap aircraft, once at night and once in broad daylight, I now realize that we failed to receive the tactical and technical information that could have allowed us to submerge before the bombs fell.

With regard to our own submarine operations, information was held so tightly that I. as a co, was normally kept in the dark on my patrol assignment until the day of, or day prior to departure. Specific orders to my assigned patrol areas were usually handed me in a sealed envelope on the day of departure, with instructions not to open until at sea. On two occasions I was told (in great confidence) — on the day prior to departure — only the general area I was being sent to. Thus, I had little time to dig up information on my own. Further, I was never given an intelligence briefing prior to departing on patrol which described the conditions to be expected in the patrol area; i.e. the best hunting areas, types and volume of ASW activity, fishing fleet activity, suspected mine fields, etc.

Nor   was  there  an  intelligence debriefing on return from patrol. Much has been said about the value of ULTRA messages sent to submarines. There is a general impression that many ULTRAs were sent to submarines, producing many attacks on Japanese ships. Perhaps so, but in my own experience, this was not true. I remember receiving only two ULTRAs  during my  last  five  runs. The  first  was in the fall of 1943. No contact resulted. A second ULTRA in the early spring of 1944 also failed to produce a contact. These results might have been affected by confusing instructions for determining expected contact positions near the equator.


Few   military  people  recognize  the wide  scope of Intelligence information. It embraces all the information necessary for military commanders to effectively plan and wage war against an enemy. The total information required by a commander can be subdivided into three major categories:

  • Information on enemy forces;
  • Information on own forces;
  • Information on the geographic and geophysical environments.

Each category can be divided into subcategories, and those into individual elements such as a particular mark and model of a weapon, the payload carried, an electronic signal’s characteristic, cloud cover over an ocean area, etc. Thousands upon thousands of elements are involved, and their numbers grow daily as new weapon systems and equipments are invented and introduced into the warfare arena. It may be that no single command requires information on all possible elements, but every level of command — from a single submarine to the Joint Chiefs of Staff — requires some of them.


Military       commanders  are     generally        familiar with the term force ratio. A concept similar to that of “Force Ratio” applies to the use of intelligence information, where:

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The ability of a commander at any level, to effectively attack an enemy, can only be achieved by having readily available as much timely information on the enemy, own forces, and the environment in the area of operations as can be obtained. At the same time a commander must try to deny the enemy information on his own force . In short, his objective is to provide as high an Intelligence Ratio in a given battle area as practical. He must do whatever is necessary to increase the value of the numerator, and decrease the value of the denominator.

To illustrate this concept, .consider some of the elements of the ratio available to a submarine force commander. First, the submarine force commander must increase the quality and amount of intelligence information supplied to his submarines. This can be done by:

  • Extraction of pertinent intelligence data from the intelligence organizations of higher echelons;E
  • Extraction of pertinent data from contact and patrol reports;
  • Debriefing personnel returning from patrol;
  • Initiation of requests for tasking of all types  of  pertinent  sensor  systems;
  • Timely analysis, integration and prepara-tion of summarized data for use by himself and his submarines;
  • Timely distribution of such data to all users by all means, including tactical data nets, and
  • Briefings of submarine personnel on enemy capabilities, operational characteristics and tactics when they are in port.

Second, the submarine force commander must attempt to decrease the quality and amount of intelligence information that the enemy can obtain for distribution to his ASW forces and other units. He can do this by:

  • Varying operational deployment patterns and strategies;
  • Maintaining tight security of information on own force organization, assignments, movements, and tactics;
  • Minimizing requirements for communications from deployed units;
  • Employing deceptive  strategies;
  • Initiating tasking requests to destroy enemy C3 I facilities and ASW capabilities, and to disrupt enemy communications.

The important point is that the submarine force commander must provide his operating units with the best intelligence information possible, and at the same time minimize the enemy’s ability to gather and use information on our submarines which would be of value to his force.

The intelligence ratio concept applies equally to individual submarines. Prior to departing on patrol, the submarine commander must gather information on enemy capabilities as well as past and present conditions in the patrol area he’ll operate  in. This  includes: locations of previous ship contacts and shipping routes; potential land targets; enemy ships and aircraft weaponry, nuclear payloads, ASW capabilities, tactics and bases; probable mine fields; enemy satellite reconnaissance systems; enemy low frequency sound detection nets, sophisticated C I systems, laser and infra-red detection systems, signal intercept systems, and technical advances in equipment characteristics and performance; etc. On station, the CO must use his personnel, his intelligence information along with his crew and equipment (particularly his sensor and tactical data systems) to obtain as much information as possible on the enemy’s presence, actions and movements. He must, at the same time, deny the enemy knowledge o~ his own presence. If detected, he must use deceptive devices and tactics.


The conditions experienced  in World  War  II are gone forever. Today, force and unit commanders must consider the effects on submarine warfare of modern systems, equipments and new tactics. Any military commander who tries to plan and conduct future warfare on the basis of World War II technology and tactics will probably be defeated.

The information requirements of military commanders has exploded over the past forty years. A world War II submarine commander, for example, with his sub on the surface using a high periscope watch during daylight in clear weather would have a maximum range of about 20 n.m. to the mast tops of a ship over the horizon — about the maximum effective SJ radar range on a ship and SD range on an aircraft.  Thus,  a CO’s  area of greatest concern was about 1,250 square miles. Then the submarine’s effective gun range against land targets was less than two miles, so the CO had little need for information on land targets.

Today, with long range  anti-ship and land attack missiles on board, the CO’s area of interest has expanded to a radius of at least 1,000 n.m. This creates an area of interest of about 3,000,000 square miles, or an area some 2,400 times greater than in World War II. To be effective the CO needs information on all possible ship and land targets within range of his missiles. He also needs knowledge of the locations of enemy detection and weapon delivery systems as well as the orbital swaths of reconnaissance satellites. He must also know the characteristics of hostile detection and enemy missile homing signals — and many other things too numerous to mention in this paper.


Submarines on  patrol  have  very limited means for gathering, analyzing, and integrating intelligence information. It is therefore essen-tial that information obtained by the intelligence community flow down to this ultimate user. Critical information sometimes fails to get there due to a lack of appreciation of the user’s needs. Hence, to solve this problem, the personnel generating and analyzing intelligence information on the user’s problems should be educated by some first hand experience — being onboard to view fighting without adequate information.

In other cases important information is denied users because of a “hold close” attitude. Part of this is a matter of politics, another arises from the need to protect information sources — but this can be grossly overdone. For example, it was reported that Churchill decided not to defend Coventry against the expected German bomber raid of November 1940 because of fear that to do so would reveal that the British were able to decrypt messages encrypted by the German “Enigma” coding machine. However, a creditable cover story and other steps should have prevented the loss of this industrial center without com-promising the British secret.

In summary, despite the fact that u.s. submarines did an outstanding job in bringing the Japanese Empire to its knees, they could have done an even better job sooner if the need to provide better intelligence information to submarine CO’s bad been better understood.

We now live in a world of continually increasing advanced air, land, sea, undersea and space weapons, and C I systems of very sophisticated performance capabilities. The present day submariner’s need for intelligence information at force and operating unit levels has become many, many  times greater       than  ever  before.This  information must get to the user. In this regard, it must be emphasized that individual submarines are the submarine force commander’s weapon-delivery units, and hence the information users.

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