It’s actually impressive that the bulk of maritime law has remained similar for the last few thousand years of human history
The law of cure means that a captain is responsible for the safety and health of crew, esp sick or injured crew — a captain is responsible for ensuring crew is restored to full health (from the 12th century Rolls of Oléron)
The law of General Average (from where we get the mathematical term) means that if a ship has to dump cargo/possessions to save itself, those who did not have their items thrown over must compensate those who did so the burden is shared evenly. This was actually called upon when the Ever Given got stuck! This dates back to 800 BCE??? That’s incredible longevity for law
And the most important law of all, which is that of rescue — if a vessel is in distress, any other nearby vessels must respond to assist, regardless of nationality. This is so old that I don’t know where it came from