Should Mel Fisher have given his treasure to Spain?

The Spanish government argued that any treasure recovered from a site in international waters belonged to Spain, under the principle of "res nullius". They further asserted that the artifacts were part of the Spanish historical and cultural heritage and hence should be returned. Mel Fisher believed that the treasure was his by virtue of his discovery, salvage and ownership rights.

The question of ownership was ultimately decided by a court in the United States, which ruled that the treasure belonged to Mel Fisher. Spain did not attempt to appeal this decision.

According to the Spanish Heritage Law of 1985, any historical or archaeological heritage found within the Spanish territory belonged to the Spanish state, and any such object found outside the Spanish territory belonged to the state if a Spanish archaeologist had participated in its discovery. However, the Spanish Heritage Law also recognized the rights of private individuals or entities who had discovered and salvaged cultural objects before this law, even outside of Spanish territory, granting them the ownership of the objects, provided that they were recovered after public knowledge of the discovery and that the Spanish state had been notified.