Until recently seagrass transplantation efforts have met with limited success in areas with high wave energies. Survival in Western Australia has been markedly improved by the deployment of large, mechanically transplanted units which provide sufficient anchorage to overcome water motion. ECOSUB1 was an underwater seagrass harvesting and planting machine designed to extract and plant large seagrass units with minimal disturbance. Over 2000 sods have been planted, with an average survival of approximately 70% over 3 years. New machines (ECOSUB2) have now been constructed to improve efficiency; these are located semi-permanently on the seafloor and allow for concurrent seagrass harvesting and planting.