environment for the marker until the last possible
moment before launch. Because of the physical
difference in size between the Mk 25 marker and the
sonobuoy launch tubes, a sonobuoy launch container
(SLC) and spacer assembly (fig. 4-8) is used to launch
the Mk 25 marker from a sonobuoy launcher.
The Mk 25 marker, with the Mk 34 adapter kit
installed, is installed into the cavity half of the split
foam spacer assembly section with the U-pin of the Mk
34 adapter in the UP position. Then, remove the U-pin
and place the other half of the split foam spacer
assembly section over the marker, which completely
encloses the marker. The foam spacer assembly
containing the marker is then installed into the SLC
against the obturator. Foam pads are installed, and the
end cap is locked into slots in the SLC, retaining the
assembly inside the SLC. A JAU-1/B cartridge is
installed in the SLC, and the loaded SLC is installed in
the sonobuoy launcher aboard the aircraft.
To launch the Mk 25 marker, the JAU-1/B cartridge
is initiated through the aircraft circuitry. It develops
sufficient gas pressure inside the SLC to force off the
SLC end cap and expel the foam spacer assembly
containing the Mk 25 marker. Once out of the SLC, the
split foam spacer assembly is separated by the
airstream, freeing the marker. The airstream then
separates the Mk 34 adapter kit from the marker,
allowing them to fall to the water as separate units.
Upon entry into the water, the marker functions as
MK 58 MOD 1 MARINE LOCATION
The Mk 58 Mod 1 marine location marker (fig. 4-9)
is designed for day or night use in any condition calling
for long-burning, smoke and flame reference-point
marking on the ocean's surface. In addition to being
used for antisubmarine warfare, it is used for
search-and-rescue operations, man-overboard mark-
ings, and as a target for practice bombing at sea. The
marker produces a yellow flame and white smoke for a
minimum of 40 minutes and a maximum of 60 minutes.
It is visible for at least 3 miles under normal operating
Figure 4-9.Mk 58 Mod 0/1 marine location marker.