Mortar and pestle

[Celt]

In all seriousness, items that are hundreds of years old need to be examined by archaeologists/historians. This isn't a finders-keepers situation. Most countries have fairly strict laws. Those divers who found Roman coins off the coast of Israel had to turn them over to authorities. Pretty sure your country would want to see this as well and find out more about it. It may be insignificant, but if I understand that website, the law states clearly that you just can't keep whatever you find.

What happens in Ireland is if local heritage authority believes a site is worth placing an order on they do a survey and then put an exclusion zone in place, you can't dive or search declared heritage sites. Just some of the known wrecks in Tramore bay alone.