The eighteenth century sailor, who rammed a wad into the muzzle of a carronade then closed it off with the tompion to prevent water seeping in, would not have believed it would still be in place well over 200 years later.
Tompions (or tampions) that we see today are usually painted replicas, like the red one sitting in the muzzle of this cannon in Norfolk Island.
Surprisingly, when the wreck of HMS SIRIUS was dived on and its artefacts brought to the surface, one of the six 18 pounder carronades was still fitted with its original water-tight wooden tompion (made of maple), which had been placed there in 1790 (the year it sank) or in 1787 when SIRIUS sailed from England as flagship of the First Fleet of 11 vessels bound for Botany Bay.
When the tompion was removed from the gun, beneath it were two lengths of twisted twine spliced to a ball of string wadding.
This is probably the only example of an original tompion, over 200 years old, in existence today.