A more thorough explanation:

Rhodian law is a system or code of maritime law that is believed to have been developed by the people of the island of Rhodes, located in the Aegean Sea. According to legend, it dates back to 900 B.C. and was adopted by the Romans. However, there is uncertainty about its history and whether it actually existed.

Despite the doubts about its existence, Rhodian law has been cited as a source of admiralty and maritime law. For example, the root-principle of the highly distinctive maritime-law system of general average is clearly stated in Justinian's Digest, and the Rhodian Law is invoked as authority.

General average is a principle of maritime law that requires all parties involved in a sea voyage to share the losses resulting from a voluntary sacrifice of part of the ship or cargo to save the whole in an emergency. For example, if a ship is in danger of sinking and the crew jettisons some of the cargo to lighten the load and keep the ship afloat, the cost of the lost cargo is shared by all parties involved in the voyage.

Overall, Rhodian law is an important part of the history of maritime law and has influenced the development of modern admiralty law.