VOLUME I Multinational Maritime Tactical Instructions and Procedures

MTP 1(D), Vol. I
the East-West dimension and the second figure the North-South dimension in miles. Patrol areas
may be overlapped.
(3) NOT RELEASABLE
3325 SCREEN FOR DAMAGED SHIPS
The sector method should be used for ordering screens for damaged ships. If the speed of a damaged
ship is low, screen units should be allocated large sectors in order to provide an all around protection and so
that they can use adequate tactical countermeasures for their own defense.
3326 — 3329 SPARE
3330 MANEUVERING WITH A SECTOR SCREEN
a. Conduct of Ship Screen Units. Units are to patrol widely throughout their sectors and when
a subsurface threat exists, to choose that speed which makes for the best use of sonar in the conditions
prevailing. Units should take account of the movement of adjacent screen units in order to avoid undue
gaps. For safety reasons a unit is not to close nearer than 500 yards to the boundary separating its sector
from one occupied by another unit.
b. Conduct of Helicopter Screen Units. Helicopters are to dip randomly throughout their
sectors. They may mark-dip in advance of their sectors but must break dip within it. Helicopters operating
under tactical direction should maneuver to cover adjacent helicopter sectors left temporarily vacant. For
safety reasons, a helicopter must break dip if it closes within 500 yards of a sector boundary common to an
adjacent occupied sector.
c. Alteration of Course. If the base course of the main body or convoy is altered, screen units
continue to patrol their sectors.
d. Screening a Carrier During Flight Operations. The conduct of screen units depends on
the method used for carrier flight operations (see Chapter 6):
(1) If Method A is used, the rules in subparagraph c above apply.
(2) If Method B is used, screen units are to patrol their sectors in the upwind direction.
(3) If Method C is used, screen units should anticipate a turn into the wind by moving upwind in
their sectors.
e. Adjusting the Screen. To adjust the screen, units may be ordered to shift their sector
boundaries or to change the depth of their sector. If the tactical requirements are not met by adjusting, the
screen must be reordered.
(1) Shifting Sector Boundaries. Units are ordered to shift their sector clockwise or counterclockwise
by a specified number of tens of degrees. Such shifts should be at least 10° and must not exceed
90°. Caution must be exercised to ensure that large shifts do not result in screen units hindering the
main body and a reduction in screen protection for an excessive period of time.
(2) Changing Depth of Sector. When the situation requires a rapid change of the screen, units
may be ordered to change the inner and outer limits of their sector in the direction of or away from the
screen center by a specified number of thousand of yards. Such changes should not be less than 1,000
yards.
3-45 CHANGE 2