Many network operations rely on the flooding operation to provide long-term performance. Mitigating malicious interference in a flooding network is thus crucial in assuring availability. Recently, several protocols based on uncoordinated spread spectrum have been proposed for secure key establishment and jamming mitigation. In this paper, we present the JIM-Beam flooding protocol that randomizes the orientation of the main lobe of a node's directional antenna so that: (1) the attacker must jam in an inherently narrowband fashion, and (2) JIM-Beam is secure regardless of the attacker's computational and reaction abilities. We perform Monte Carlo simulations and show that JIM-Beam provides substantial performance improvements for packet flooding. We also discuss how combining JIM-Beam with existing antijamming schemes can provide substantial advantages to the combined system.