POSSIBLE SIGNIFICANCE OF RECENT SIGHTINGS OF SUBMARINES IN US COASTAL WATERS

• Document Type: CREST
• Collection: General CIA Records
• Document Number (FOIA) /ESDN (CREST): CIA-RDP61-00391R000100060004-0
• Release Decision: RIFPUB
• Original Classification: S
• Document Page Count: 3
• Document Creation Date: November 9, 2016
• Document Release Date: July 9, 1998
• Sequence Number: 4
• Publication Date: April 30, 1958
• Content Type: REPORT

eoJ~4.
30 April 1958
POSSIBLE SIGNIFICANCE OF Rte' SIGBrINGB OF SUBMARINES
Numerous recent sightings of submarines, ostensibly Soviet, in the
boastal waters adjoining the US may indicate more than mere reconnaissance
interest by the intruders. Although it might normally be expected that
Soviet submarines of long range would venture to the vicinity of the Atlantic
coast of the US for reconnaissance and training purposes, there is need,
nevertheless,' to consider the possibility that other specific and farsighted
Soviet objectives may underly these sightings.
It is generally recognized that enemy submarines could effectively
attack US coastal industrial areas on both the Atlantic and Pacific sides
with ballistic and air-borne missiles of 500-600 mile range launched from
positions several hundred miles offshore. The Soviets are believed to
possess long-range missile launching submarines in sufficient numbers to
carry out such an attack. For guidance of these missiles, the Soviets might
plan to rely ultimately upon homing devices clandestinely placed at the
selected targets. On the other hand, ballistic missiles require that accurate
relative positions of the launch'point and target be available at the time of
launching. Space limitations pointtoverd the ballistic missile as more
suitable for submarine launching. Since the risk of detection in the placement
of homing devices and in the transmittal of messages of instruction is rather
great, we believe the Soviets would exploit other promising methods of
guidance control to insure accurate targeting and maximum damage.
A routine determination of position at sea by the usual'methods of
celestial navigation and observing the sun gives a value correct to approximately
one ail*. When weather conditions are favorable so that observations can be
repeated, the error might be half a wile or less. On the other hand, if
prior to lavLt'iing a mittile, the probable error in position might be several
miles. It is evident that in any.projection of war plans for submarine attack
against the L with ballistic missiles, the destruction, of targets would be
greatest !,f the positions v ere accurately known of the Soviet submarines. In
some manner, the Soviets would have to solve this positioning problem at sea,
to have an attack potential for achieving thesaximum damage to US targets.
Approved For'Relehse P61 -00391 R000100060004-0
Approved For Rele '' i ``' ODP61-00391 R000100060004-0
 -Approved For ReI DP61-003918000100060004-0
There in evidence in current open literature that the Soviets are fully
aware of a need for greater accuracy in determining sea positions. Actually
it has largely been under the stimulus of accuracy considerations for
navy-launched IRBMs, and ICBMs, that attention has lately been focused on
this problem in the US. The probhble error of one mile does not bother the
navigator on a merchant ship far from land, but it does affect signific'fntly
the planning of weapons systems where the greatest damage must result from
a single shot at long range.
The following analysis presupposes a Soviet decision to rely upon the
ballistic missile attack against the US with submarines, in the event of war.
There is presenteda programbriefly of what the Soviets may currently be
doing to improve their positioning capabilities over the 1irth American
continental shelf at places' selected as potential missile launching positions.
It is believed to be technically possible within the limits of current
practice to construct a mechanism enclosed within ashell, for which the
following Would be trues
1. It 'would be dropped, ejected, or anchored into the sediments of
the lehallov sea bottcsa in depths up to 600 feet, so that it would
not drift under the influence of prevailing ocean currents.
2. The sealed outer shell would provide a protective coating against
corrosion, no-that an operable life of several years is assured the inner
mechanism.
3. The inner mechanism itself is a sensing system, capable of. identifying
a coded emend signal from a friendly ship. Upson receipt of the coded
54gn81,? the mechanism would produce a sound signal of predetermined.
strength, and dulation.
Itis possible that the Soviets have already developed such "submerged
5'
position indicators" (SRI), for uttimate possible use in spotting the positions
t sales' oiahasm l:pan s+aje etl UB targets. Let
us suppose that it is t& price objective of the recently sighted Submarines
to lay these BPI deviccs?and they dateraine and test their locations. After
dropping one the subs*riue Would surface and determine its position by celestial.
navigation. T. SWM"ine then ezuises about, sends out the coded signal and
gets the ditrectional sound Signal back from BPI which enables the submarine
Approved For Rel " . RDP61-00391 R000100060004-0
 'Approved For Relea icy :fr, -RDP61-00391 R000100060004-0
again to surface immediately over it. The multiplicity of determina,,1onb
of position thus possible would afford a very accurate astronomical
of the coordinates of that particular SPIT. ldont.b later, back in the !.TSSE,
the astro-coordinates could be computed into geodetic coordinates on the east
geodetic system as the target whose position is already well known from US
maps. Subsequent cruises by other submarines could reestablish the c.oordinatt74
formerly ascertained, and thus check on any possible drift. Also the continufr,
operability of the forty or fifty devices of this sort which might be laid
could be checked from time to time.
In the event of war, the submarines would take up positions above their
assigned SPIs, thus reducing to the very minimum the uncertainty associated
with their positions at sea. At the prearranged time, they would all surface
and fire .
In the event that such a program would be under Soviet consideration,
today, it would probably be in the earliest stages when one or two of the
devices are being set and tested. The intelligence effort to detect such a
program would involve:
1. By studying charts of the shelf floor, decide where a number of
positions for such devices might be I. favorable for firing at
selected targets.
2. Watch particularly for recurring appearances of unidentified
submarines in approximately the same position at Bea.
Intercept any sound signals In the vicinity of sighted submarines.
4. Watch for any unusual Soviet interest in obtaining US oceanographic.
material.
5? Watch Soviet technical literature for indication of intense interest
in related sound-in-water problems.
Approved For Release CIA-RDP61-00391 R000100060004-0