In the summer of 1632, Fermin Mazalet was planning a swindle based on a proposal to raise, or at least salvage, the Vasa, using information from books he had stolen from Grantville's library. Up-timer Ginny Cochran, an assistant librarian newly assigned as the assistant to the New United States' consul in Stockholm, had her own plans to salvage it using a pump-fed diving bell.
- Summer of 1632 is an estimate based on internal references in "Diving Belle".
- Diving bells existed in 1632, but the idea of pumping air into them was not suggested until 1689, and was not used until 1789.
- In 1663–1665, many of the Vasa's cannon were recovered by divers working from a diving bell. While this is not explicitly mentioned in "Diving Belle", it is implied that Ginny Cochran may have been aware of it.
Ring of Fire II, "Diving Belle"