After protesters dumped the tea into the harbor 250 years ago, they tossed the chests it had been in into the harbor as well. J.L. Bell posts a copy of an account by Rev. Dr. John Prince of Salem, who watched the Tea Party and then returned to the wharf the next morning:
The ebb tide carried most of it away, and the empty chests were seen floating down the harbor on the Dorchester shore in a line, extending to the castle.
Castle William, on an island out in the harbor, is today known as Fort Independence at Castle Island, in what is now South Boston.