Subsurface marine heatwave information is important for agile marine management. Heat content of the top 300 metres of the water column and temperature-at-depth is an important driver of health and productivity of fisheries and aquaculture for creatures that reside and forage deeper than the surface layer of the water column. Methods applied to develop seasonal forecasts of surface marine heatwave risk from dynamical ocean-atmosphere models can likewise be applied to subsurface metrics such as heat content and bottom temperatures on the continental shelf. The Australian Bureau of Meteorology's seasonal forecast model ACCESS-S2 currently produces experimental products based on marine heatwave metrics using subsurface forecasts and probabilities of exceeding the 90th percentile. These products will complement surface marine heatwave products to provide a comprehensive view of potential marine ecosystem stressors and aid in the management of these events, particularly important in a changing climate.