The Mk 34 adapter kit is used when the Mk 25
and Mods marine location marker is
launched from sonobuoy launchers.
The Mk 58 Mod 1 marine location marker is
used for antisubmarine warfare, search-and-
rescue operations, man-overboard markings,
and as a target for practice bombing at sea.
The Mk 58 Mod 1 marker produces a yellow
flame and white smoke for 40 to 60 minutes.
Under normal conditions, the flame and/or
smoke of the Mk 58 Mod 1 marker is visible
for 3 miles.
The Mk 58 Mod 1 marine marker is hand
launched, externally launched from aircraft
bomb racks, or launched from sonobuoy
The Mk 72 Mod 1 seawater-activated battery
is used with the Mk 58 Mod 1 marker.
PRACTICE BOMB SIGNAL
LEARNING OBJECTIVE: Identify the pur-
pose and use of practice bomb signal car-
Practice bomb signal cartridges are used for day
and night operations and as a visual indication of bomb
impact and fuze function. Three types of signal
cartridges are discussed in this section.
Mk 4 Mod 3 signal cartridge. The Mk 4 Mod 3
practice bomb signal cartridge (fig. 4-11) consists of an
aluminum case. The rim end has a percussion primer,
and the opposite end is sealed with an aluminum disk.
The cartridge produces a flash of light and a white
smoke puff. The Mk 4 Mod 3 is primarily used for night
CXU-3A/B signal cartridge. The CXU-3A/B
practice bomb signal cartridge (fig. 4-12) consists of a
cylindrical aluminum case. The case is closed on one
end with a percussion primer, and the opposite end is
closed with a crimped-in-place aluminum cover (cap).
The cartridge produces a dense, white smoke display
for day missions.
CXU-4/B spotting charge. The CXU-4/B spotting
charge (fig. 4-13) is a fire-free signal used with practice
bomb BDU 45/B to provide a daytime visual indication
of bomb impact point and fuse function.
Figure 4-11.Practice bomb signal cartridge.
MK 4 MOD 3:
Figure 4-12.Mk 4 Mod 3, CXU-3A/B practice bomb signal
Figure 4-13.CXU-4/B spotting charge.