I think the place is called Oak Island.
Oak Island is indeed the place that the original poster asked about.
After some time they find oak platform, cut through, keep digging, keep finding more platforms. Eventually they can't dig anymore and get help. But they came back the next day to find the hole filled with sea water, which resisted all attempts to pump it out. If true, and if there was a sealed chest down there, this ruined any chance of recovering it intact. Any paper goods are now probably goo.