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Figure 6-5. Planning Data Sources.

Figure 6-5. Planning Data Sources.

preliminary dives by senior, experienced members of the team can be of great value in verifying, refining, and analyzing the data to improve the dive plan. This method saves diver effort for recovering items of interest.

6-5.2.3 Identifying Operational Hazards. Information must be collected to help identify hazards. For example, a diver working around a ship shall know the location and status of ship sea suctions and discharge points, propellers, rudders, diving planes, and sonar transducers. If working on or near a vessel that has a nuclear propulsion system, the diver shall be aware of radiological hazards, rules for working on or near such a vessel, and the locations of the reactor compartment, discharges, etc. Most importantly, the diver shall be briefed on potential exposure and shall wear proper underwater radiological exposure detection instruments.

6-5.3 Data Required for All Diving Operations. Data involving the following general categories shall be collected and analyzed for all diving operations:

■ Surface conditions

■ Underwater conditions

■ Equipment and personnel resources

■ Assistance in emergencies

6-5.3.1 Surface Conditions. Surface conditions in the operating area affect both the divers and the topside team members. Surface conditions are influenced by location, time of year, wind, waves, tides, current, cloud cover, temperature, visibility, and the presence of other ships. Completing the Environmental Assessment Worksheet (Figure 6-6) helps ensure that environmental factors are not overlooked during planning. For an extensive dive mission, a meteorological detachment may be requested from the local or regional meteorological support activity.

6-5.3.2 Natural Factors. Normal conditions for the area of operations can be determined from published tide and current tables, sailing directions, notices to mariners, and special charts that show seasonal variations in temperature, wind, and ocean currents. Weather reports and long-range weather forecasts shall be studied to determine if conditions will be acceptable for diving. Weather reports shall be continually monitored while an operation is in progress.

NOTE Diving shall be discontinued if sudden squalls, electrical storms, heavy seas, unusual tide or any other condition exists that, in the opinion of the Diving Supervisor, jeopardizes the safety of the divers or topside personnel.

6-5.3.2.1 Sea State. A significant factor is the sea state (Figure 6-7). Wave action can affect everything from the stability of the moor to the vulnerability of the crew to seasickness or injury. Unless properly moored, a ship or boat drifts or swings around an anchor, fouling lines and dragging divers. Because of this, any vessel being used to support surface-supplied or tended diving operations shall be secured by at least a two-point moor. Exceptions to diving from a two-point moor may occur when moored alongside a pier or another vessel that is properly anchored, or when a ship is performing diving during open ocean transits and cannot moor due to depth. A three- or four-point moor, while more difficult to set, may be preferred depending on dive site conditions.

Divers are not particularly affected by the action of surface waves unless operating in surf or shallow waters, or if the waves are exceptionally large. Surface waves may become a serious problem when the diver enters or leaves the water and during decompression stops near the surface.

6-5.3.2.2 Tender Safety. Effective dive planning shall provide for extreme temperatures that may be encountered on the surface. Normally, such conditions are a greater problem for tending personnel than for a diver. Any reduction in the effectiveness of the topside personnel may endanger the safety of a diver. Tending personnel shall guard against:

Sunburn and windburn

■ Hypothermia and frostbite

■ Heat exhaustion

Figure 6-6. Environmental Assessment Worksheet. The Environmental Assessment Worksheet indicates categories of data that might be gathered for an operation. Planners may develop an assessment methodology to suit the particular situation. The data collected is vital for effective operations planning, and is also of value when filing Post Salvage Reports.

Figure 6-6. Environmental Assessment Worksheet. The Environmental Assessment Worksheet indicates categories of data that might be gathered for an operation. Planners may develop an assessment methodology to suit the particular situation. The data collected is vital for effective operations planning, and is also of value when filing Post Salvage Reports.

Sea State

Description

Wind Force (Beaufort)

Wind Description

Wind Range (knots)

Wind Velocity (knots)

Average Wave Height (ft)

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