2. Typical gap-crossing operations are:
a. fixed and floating bridges;
b. ferries and rafting;
c. assault boat crossings;
d. vehicle and personnel fording; and e. amphibious crossings.
3. Combat divers may be employed during the conduct of all stages of a gap-crossing operation. Typical tasks they may be required to perform when supporting the in-place and bridgehead forces are:
a. conduct reconnaissance of the potential crossing sites, especially the bottom profile and far bank;
b. breach obstacles in the water and on the far bank, including mined areas;
c. mark exit points and any obstacles in the water that would affect the crossing operation;
d. form part of the safety organization if it is determined that divers are needed as part of that organization; and e. as part of the assault echelon, combat divers can assist infantry reconnaissance parties on the water and inland within proximity of the waterline as guides for the bridgehead and breakout force.
4. Gap-crossing operations are considered as either hasty or deliberate:15
a. The hasty crossing operation is normally executed from the line of march using resources within the force. Very little reorganization of the assault echelon is required, and drills may be developed for crossing to commence with little or no additional orders being given. Some crossing assets, such as AVLB or Medium Raft (MR) may be pushed forward to allow a hasty crossing of more difficult water obstacles. Divers may not be employed in most hasty crossings due to a lack of time. They could be used to confirm and mark a ford or remove demolitions from a bridge that has been captured.
b. A deliberate crossing operation is only undertaken when no other option is available. Deliberate crossings require thorough reconnaissance, detailed planning, extensive preparations, rehearsal, and heavy or specialist engineering equipment. It is
14 The commander may determine that no safety organization is required or that safety lines and surface boats are sufficient. This is not a recommended solution, but the type of safety organization in an operation will depend on many factors. Divers will only be one part, if at all, in such an organization.
15 B-GL-361-001/FP-001 Land Force Engineer Operations, Chapter 7, Section 2 describes crossing operations in detail.
conducted because of the complexity of the obstacle, the strength of the enemy, or when a hasty crossing has failed. While it is often considered that only a division could perform a deliberate crossing operation, it can be performed by a battle group or brigade, depending on the extent of enemy opposition. A deliberate crossing will involve the regrouping of resources and more complete reconnaissance of the water obstacle. Combat divers will be employed to confirm the selected crossing sites and the far banks of those crossing sites. They could assist the assault force by marking beachheads and supporting the preparations of the in-place force by clearing obstacles.
c. In either operation, divers may be employed to recover equipment or bodies after the successful completion of the crossing operation.
5. Reconnaissance Considerations. Combat divers may be used to conduct a reconnaissance to confirm the suitability of a crossing site. They can identify the extent of preparation, if any is required, and confirm the presence and extent of mines and obstacles. Geomatics, air and satellite imagery as well as HUMINT will assist in identifying potential crossing sites and allow for the efficient employment of combat divers and economy of effort.
6. Reconnaissance Details. The Crossing Site Recce Report, E112B (DND 2106) outlines the technical data required to support a gap-crossing operation. In addition to the details of the E112B, the minimum details combat divers should attempt to gather are the following:
b. Water depth—when the water is deeper than the snorkelling depth of the AEV, the depth of the water is no longer relevant. It is critical to know the more shallow depths, and to a greater accuracy, as those will affect bridges and rafts.
c. Natural and emplaced obstacles, including mines.
d. Bottom type and estimated ground-bearing pressure of approaches and landing site.
e. Speed of current.
f. Condition and slope of banks and work required.
g. Exits on the far bank from the beach area. Approaches should also be considered, but that information can be gained from a multitude of sources.
h. Enemy activity.
7. Reconnaissance of a Crossing Site. Combat divers may conduct this task as surface swimmers, with breathing apparatus, or using a combination of techniques. Enemy threat and capabilities and the physical characteristics of the objective will be deciding factors in the approach and equipment used. A passage through friendly lines will have to be coordinated for this task. The general procedure for a gap-crossing recce is as follows:
a. a team of combat divers approach the beach with or without breathing apparatus;
b. the objective is secured;
Mobility (Crossing and Breaching Operations)
c. the required details are gathered;
d. the team regroups, leaves the objective; and e. disseminates information at an operational Rendezvous (ORV).
8. This task may be conducted in pairs or as a team. Factors that will decide the size of team are the extent of reconnaissance required and the size and complexity of the obstacle. Generally, one pair will be able to conduct a reconnaissance of one crossing site. If time permits, they may be re-tasked to reconnoitre another site.
9. Procedure as a Pair. To conduct a crossing-site reconnaissance as a pair:
a. the combat divers enter the water at the site or upstream of the proposed crossing site;
b. move down the river to the proposed site;
c. conduct an initial assessment of the site suitability and gather required details; and d. continue downstream to an RV point where they may link up with other divers and disseminate information.
10. Pairs of divers should be assigned specific sections of the obstacle. The length of each section must be determined by the availability of divers and the time to conduct the task. Their responsibilities are:
a. diver 1—provide security; and b. diver 2—gather reconnaissance details.
11. This method can quickly provide a crossing-area commander with confirmation of suitable sites and the extent of preparations required. This is the preferred method when conducting a hasty crossing operation, but it could also be used for deliberate crossing operations.
12. Procedure as a Team. Combat divers working as groups of six can gather more accurate details required when planning a deliberate crossing operation. In other cases, the water gap is large enough or the site complex enough that a dive team may be required to do the reconnaissance. The dive team will normally concentrate on the reconnaissance, and the manoeuvre forces or force in place will provide security. (If it is a good site for us, it is a good site for the enemy and therefore should be guarded by our own forces.) The general concept is as follows:
a. the home bank is secured by elements of the manoeuvre unit;
b. the dive team conducts a bottom profile with a reel of line and/or handheld sonar;
c. the dive team confirms the presence and extent of obstacles or mining; and d. RV and disseminate information.
Mobility (Crossing and Breaching Operations)
13. Responsibilities of the team members are:
a. Divers 1 and 2—gather recce details of the home bank.
b. Divers 3 and 4—gather recce details of the far bank.
c. Divers 5 and 6—provide security and backup divers. in addition, the team leader should be in this pair and control the task.
14. Reconnaissance information requirements may vary for several reasons. Divers must be able to adapt the reconnaissance to suit the limitations and capabilities of the gap-crossing equipment that will be used.
15. Landing Site Reconnaissance. The techniques used for a crossing-site reconnaissance may be adapted for a landing site along a linear water obstacle, such as an ocean beach. This operation will not be conduced as an opposed water crossing, but it may be necessary for combat divers to assist in the use of beaches for logistical reasons. The navy is normally responsible for all clearance activities up to the high-water mark, but combat divers may have to supplement the naval capability. This type of operation will require specific training as it is a complex operation that requires a thorough understanding of the tides, types of landing craft and ground-bearing requirements for the vehicles arriving on shore. It is included here for information purposes. A beach on a lake or river, used to support assault boats or rafts, is handled in the same way as a normal exit reconnaissance. Factors that make this task different from a river-crossing site are:
a. action of the surf;
b. tidal zones and the effects of tides;
c. the objective is generally linear and large;
d. characteristics and nature of the beach and shoreline; and e. boat and ship drills are often conducted in rough water.
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