6 - 7 b. Navigation. While navigating during limited visibility, the unit uses the same techniques are they do in daylight, but leaders exercise more care to keep the patrol oriented. c. Security. • Enforce strict noise and light discipline. • Use radio listening silence. • Use camouflage. • Use terrain to avoid detection by enemy surveillance or night vision devices. • Make frequent listening halts; conduct SLLS (Stop, Look, Listen, Smell). • Mask the sounds of movement when possible. (Rain, wind, and flowing water will mask the sounds of movement.) d. Rally Points. Leaders plan actions to be taken at rally points in detail. All elements must maintain communications at all time. The two techniques for actions at rally points follow: • Minimum Force: Patrol members assemble at the rally point, and the senior leader assumes command. When the minimum force (designated in the OPORD) is assembled and organized, the patrol will continue the mission. • Time Available: The senior leader determines if the patrol has enough time remaining to accomplish the mission. e. Actions at Halts. During halts, the unit posts security and covers all approaches into the sector with key weapons. • Short Halt. This typically takes 1 to 2 minutes long. Rangers seek immediate cover and concealment and take a knee. Leaders assign sectors of fire. • Long Halt. This typically takes more than 2 minutes. Rangers assume the prone position behind cover and concealment. Leaders ensure Rangers have clear fields of fire, and assign sectors of fire. 6-7. DANGER AREAS. A danger area is any place on a unit’s route where the leader determines his unit may be exposed to enemy observation or fire. Some examples of danger areas are open areas, roads and trails, urban terrain, enemy positions, and natural and manmade obstacles. Bypass danger areas whenever possible. a. Standards. • The unit prevents the enemy from surprising the main body. • The unit moves all personnel and equipment across the danger area. • The unit prevents decisive engagement by the enemy. b. Fundamentals. • Designate near and far side rally points. • Secure near side, left and right flank, and rear security. • Recon and secure the far side. • Cross the danger area. • Plan for fires on all known danger areas. c. Technique for Crossing Danger Areas. (1) Linear Danger Area (LDA; Figure 6-4) Actions for a Squad. STEP 1. The alpha team leader (ATL) observes the linear danger area and sends the hand and arm signal to the SL, who determines to bound across. STEP 2. SL directs the ATL to move his team across the LDA far enough to fit the remainder of the squad on the far side of the LDA. Bravo team moves to the LDA to the right or left to provide an overwatch position prior to A team crossing. STEP 3. SL receives the hand and arm signal that it is safe to move the rest of the squad across (B team is still providing overwatch). STEP 4. SL moves himself, RTO and B team across the LDA. (A team provides overwatch for squad missions.) STEP 5. A team assumes original azimuth at SLs command or hand and arm signal. (2) LDA Crossing for a Platoon. (a) The lead squad halts the platoon and signals danger area.