d. During the movement to contact, the maneuver force may encounter natural and man-made
obstacles that impede its movement. The swift crossing or breaching of these obstacles is crucial in
maintaining the momentum of the attack. An unnecessary delay may provide the enemy the time to
reinforce defensive positions or to reconsolidate forces and launch a counterattack. Friendly maneuver
forces are susceptible to enemy direct and indirect fire while preparing for and crossing obstacles.
Major obstacles include water and minefields.
e. During river crossing operations, the maneuver unit must be concealed as it occupies the near
shore, as it crosses lead elements to establish a bridgehead and gain overwatch positions on the far
shore, and as it crosses its main elements. In addition to the smoke screen at the actual crossing site,
smoke units should place several deceptive smoke screens to confuse the enemy. Smoke units
supporting a river crossing will be under the operational control of the crossing site commander. Figure
1-20 illustrates smoke support of a river-crossing operation.