Abstract: This work focuses on the requirements of "better than best effort" (high hop-by-hop delivery guarantee) broadcast in highly dynamic mobile multi-hop ad hoc networks (MANETs). Our work is motivated by mission-critical applications such as disaster relief and military operations. This class of applications is characterized by: (1) high delivery guarantee requirements even in the presence of high mobility, and (2) broadcast-style of communication where all nodes are receivers. Extensive simulations conducted on two different platforms show that, as node speeds, network traffic load, and number of senders increase, the performance of existing multicast protocols (exemplified by ODMRP and MAODV) degrade in terms of packet delivery and overhead. In contrast, simple flooding, while clearly not a panacea, performs comparatively well and shows promise as a foundation for more specialized protocols for highly dynamic MANETs of the future.