If the goAl is reduction of emissions or generic environment friendliness biodiesel is not a solution. Especially if the biodiesel comes from palm oil.
It very much depends on the source - palm oil is a disaster but if there are alternatives it seems like it would be a net win for CO2 if you could avoid additional fossil fuel extraction. I’m thinking of a guy I knew who used to process oil from a local restaurant’s deep fryer – that would be problematic getting the formulation right for an advanced car engine but my (possibly completely incorrect) understanding is that marine Diesel engines are a lot simpler and there isn’t an obvious path for short-term replacement the way there is for an EV.