In Canada, provinces and territories all have legislation to protect heritage writ large. I can give you two examples. B.C., for example, has very strong protection for underwater cultural heritage. Any wreck that's been abandoned or wrecked is automatically subject to the law after two years, so you need a permit to do any research on those wrecks. It's a two-year limit.
On March 19th, 2018. See this statement in context.