Fishing is a major industry that provides the livelihood for millions of families worldwide. The fishing vessels are typically at sea for 5-7 days at a stretch completely cut off from the land. In a low-cost offshore communication system for fishermen currently being developed, a multilevel P2MP backhaul network connects clusters of boats at the fishing zones. Each cluster forms a wireless mesh network with multiple potential gateways to the backhaul network. This work proposes a resilient lightweight protocol for optimized dynamic provisioning of the backhaul network based on an adaptive, demand driven algorithm. A local controller, capable of running on any access router, selects the optimal subset of gateways so that the rest can be reconfigured as mobile base stations or switched to power saver mode. It assigns every boat in a cluster to the most appropriate gateway maximizing the utilization of gateways. A proof-of-concept implementation has been done with a hardware test bed and the results are very encouraging.