The broader impact of this SBIR Phase II project will be to address the rate of coral reef degradation. An estimated half of all coral reefs have already been lost. Current restoration efforts can restore on the order of one hectare per year while the world is losing on the order of one million hectares of reef per year. The goal of this project is to scale up coral restoration capacity worldwide to a level that keeps pace with the rate of coral mortality. Through this project, development of an automated coral planting system will remove the rate-limiting manual labor from coral out-planting, providing a dramatic increase in worker productivity in reef restoration. This development will enable construction of low-cost fleets of planters to repopulate damaged coral reefs. It will also promote widespread application of knowledge about coral health and enhanced resilience, needed to keep corals alive in a changing ocean climate. Healthy reefs then can provide habitat for food species, physical protection for coastlines, and income for tourism-based economies. The focus of this project is development of an automated coral planting system to rapidly attach corals to a degraded reef. The major technical innovation is to provide both a physical installation toolset and navigation capability in a chaotic shallow water environment such that the vehicle can plant hundreds of corals per hour. The primary technical direction proposed is to use a nearly neutrally buoyant underwater vehicle to navigate the reef and perform the planting operations. The vehicle will carry trays of corals from nurseries and have an internal coral management system to feed them into a planter. When the vehicle has selected a suitable planting location using a combination of inertial and acoustic navigation and vision sensors, it will clear a surface of rubble and algae, drill a hole, and insert a coral into the hole, permanently attaching it. Each vehicle greatly multiplies the planting rate of an operator. As autonomous behaviors are implemented through this project, each operator will be able to handle fleets of vehicles, raising coral planting rates to a level that begins addressing the rate of coral loss.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.