I would like to share my point of view with you as a legal expert in both civil & common law.

Good faith is a principle of a reasonable contract where all parties are satisfied with their agreements. In general, civil or common law consider that good faith requires fair expectations which future contractors negotiate before they have a written agreement on all clauses.

The circumstances that determine wrongdoing or unjust enrichment in maritime contracts are not always clear even nowadays, yes, we built good information system as evidence to prove who is responsible, but the burden of proof stays the big issue in law debates.

For instance, in a previous research I carried where I used law and economics theory to see with a "market eye", I concluded that the statement of who has the real obligation to prove that goods, in the ship, were treated with due care after a fire is not fair. All international conventions give protection to ownership instead of shipper even If he met his contract obligations and cannot know if his goods were in good conditions to support the voyage.

So, in shipping contracts the good faith depends on typical contracts: labour contracts, bill of landing, charterparty, contracts with different port operators, etc.
In the sea, we always have new risks and the sector used to deal with the probability of danger especially nowadays with all new techniques et technology to manage global challenges.

Today, Covid-19 made contradictions arising in the sector even If we all know internationally that six (6) mouths ago the situation was conceited as "force majeure". Now, two elements are gone: unpredictability and irresistibility but we cannot manage first element exteriority. In this case, we need, all entities, to cooperate with good faith which only equitable negotiations can make it happen.

Concerning the interpretation of a good faith in jurisdiction in different countries depends mostly on the type of contracts and when we talk about the weaker party in a contract, we talk about many rules of protection.

The main problem is not in practice but in a doctrinal debate of relational contract theory.