The energy transition process is fundamental for reducing greenhouse gas emissions in the atmosphere. The maritime sector, responsible for 3 per cent of global emissions, is also a crucial player in the transition. The International Maritime Organization aims to operate with a mixture containing at least 5 per cent biofuels in conventional marine diesel fuel by 2030. This study focuses on evaluating the combustion impact of ternary mixtures containing marine diesel and biofuels such as ethanol and biodiesel at different concentrations using the numerical simulation tool CONVERGE CFD. The simulations were conducted in a pre-modeled engine by the software with the following parameters: 2440 cc displacement, a compression ratio of 16, and a rotational speed of 1600 rpm. This configuration remained the same for all simulations of the 8 involved mixtures, which are: 100 per cent marine diesel (DIESEL), 3 bin ary mixtures containing 5 per cent, 15 per cent, and 30 per cent ethanol in the marine diesel mixture (DE05, DE15, and DE30, respectively), followed by a binary mix ture of 20 per cent biodiesel with the marine diesel mixture (B20), and finally 3 ternary mixtures containing 20 per cent biodiesel and varying ethanol concentra tions (5 per cent, 15 per cent, and 30 per cent) in the marine diesel mixture (B20E05, B20E15, and B20E30, respectively). The mixtures containing biodiesel demonstrated promising results regarding the heat release rate, with the B20E30 mixture showing the best result, with an increase of 42.82 per cent compared to DIESEL, in addition to having the highest efficiency among the mixtures, 4.17% above DIESEL. However, this mixture showed the worst results in soot and CO2 emissions, with increases of 19.67 per cent and 17.02 per cent compared to DIESEL, re spectively. The B20 showed the best results for reducing HC and CO emis sions compared to DIESEL, with reductions of 72.72 per cent and 73.61 per cent, respect ively. The use of ethanol with marine diesel negatively impacted emissions. The DE30 showed the worst results in NOx, HC, and CO emissions, with increases of 19.67 per cent, 4.80 per cent, and 5.58 per cent, respectively.