What is the first action you should take when hearing the sound of a rising flare?

When hearing the sound of a rising flare, assuming a prone position is the appropriate initial action. This position helps ensure maximum concealment and minimizes the chances of being seen by enemy forces. By getting low to the ground, a Marine can effectively reduce their silhouette against the terrain, which is crucial for maintaining covert status.

Taking cover immediately may suggest seeking immediate shelter or protection, but without further assessment of the environment, it could lead to exposing oneself to potential threats. Signaling for backup, while an important tactical decision, assumes there is already a known threat or necessity for assistance, which may not be the case upon merely hearing a rising flare. Moving to higher ground could provide a better vantage point but also exposes the individual to greater visibility and potential risk.

Therefore, the first action should be to assume a prone position, allowing for readiness to assess the situation while maintaining a low profile.