A more thorough explanation:

Usura maritima is a Latin term that refers to the interest charged on a bottomry or respondentia bond. This interest is proportioned to the risk involved and is not restricted by usury laws.

For example, if a ship owner takes out a loan to repair their vessel, they may offer a bottomry bond as collateral. The lender would then charge interest on the loan, which would be proportionate to the risk involved in lending money for the repair of the ship. This interest would be considered usura maritima and would not be subject to usury laws.

Another example would be a respondentia bond, which is a type of loan secured by the cargo of a ship. The interest charged on this type of loan would also be considered usura maritima.

Usura maritima is a term used in maritime law to describe the interest charged on loans that are secured by a ship or its cargo. The interest charged is based on the risk involved in lending money for these purposes and is not subject to usury laws, which typically limit the amount of interest that can be charged on a loan. This allows lenders to charge higher interest rates on these types of loans, which helps to offset the risk involved in lending money for maritime purposes.