RECAST could deliver decarbonisation of shipping with conventional engines, using lime as a sorbent and as part of the fuel for the ship. The system involves (i) on-land processing of limestone (CaCO3) to low-emissions lime (CaO) in a Calix LEILAC calciner, which can capture the process and heating CO2 emissions for minimal energy or operating penalty (www.project-leilac.eu ), and will be fuel agnostic, (ii) Sequestering the captured CO2 (CCS/CCU), (iii) Using the low-emissions lime to capture the CO2 from ship stacks (bunker fuel, marine diesel or LNG) using Calix’s Direct Capture Technology. NOx and SOx reductions are also being targeted with additives, (iv) Using the heat released by CaO recarbonation and fuel slip oxidation in the scrubber and engine waste heat to generate further motive power. Initial estimates suggest over a 1/4 increase in range per tonne of bunker fuel / LNG. Initial estimates indicate the cost of CO2 avoided could be as low as US$70/t, depending mainly on lime costs. The innovation is to bring these technologies together in RECAST at a commercial scale on a ship, in combination with zero emissions lime production on land. This paper describes the system, and the development steps by which it will be fully demonstrated.