[2] With the financial support of Christopher Blake, an English gambler, Day built a wooden "diving chamber" without an engine.
The sloop's hold contained 10 tons of ballast, and two 10-ton weights were attached beneath the keel which could be released from inside the diving chamber.
An additional 20 tons of ballast would be loaded on the Maria after Day had been locked inside the diving chamber.
[5] He bet with Blake that he and his boat could descend to a depth of 130 feet (40 m) and stay underwater for 12 hours.
[3] It has been speculated that Day may have died from asphyxiation,[1] hypothermia[4] or catastrophic structural failure of the Maria and/or the diving chamber due to water pressure.