The buoyancy jacket and the octopus.

Fenzy and the adjustable buoyancy life jacket

Most of the early history of the buoyancy compensator rests on Wikipedia, which cites an archived history of the device. Wikipedia says Maurice Fenzy, founder and owner of the French firm Fenzy (founded in or before 1920), invented the adjustable buoyancy life jacket, or ABLJ, in 1961, and that the firm's name became a byword for the item. Wikipedia's general history of scuba says adjustable buoyancy life jackets became available during the 1960s.

The stabilizer jacket: 1971 or 1978

The wrap-around jacket style that followed the early life jackets is associated with ScubaPro, but its date is disputed, and the manufacturer's own pages appear to give both years:

• Wikipedia says ScubaPro introduced the stabilizer jacket in 1971.
• ScubaPro's own timeline, seen as a search summary, calls its 1971 Stabilizing Jacket the first in the industry. That is a manufacturer's claim.
• Other search summaries, including one of ScubaPro's 60th-anniversary page, describe ScubaPro engineers combining two horse-collar devices into a wrap-around Stabilizing Jacket in 1978.

ScubaPro's history page did not load during our research, so the date could not be settled from the company's own record.

ScubaPro's own beginnings

Blutime Scuba History, a diving-history site, says ScubaPro was founded in 1963 by Gustav Dalla Valle (spelled Della Valle on that site) and Dick Bonin, after Healthways went bankrupt in December 1962, and that Dalla Valle sold the company to the S.C. Johnson group in 1974. Where it started is told two ways: Blutime says California, while a biography of Bonin by the International Scuba Diving Hall of Fame, seen only as a search summary, places the start in Chicago. We could not confirm the Chicago version.

The octopus

Wikipedia describes the "octopus" as a redundant second-stage regulator. Quebec's official terminology office explains the name as coming from the look of a diver's many hoses. Wikipedia also notes that it is attached to the diver's own main gas supply, which means it is not a separate supply for the diver who carries it.

Its roots are linked to cave diving. Wikipedia says Sheck Exley helped standardise the use of the octopus in cave diving. Wikipedia also says La Spirotechnique pursued single-hose regulators partly so that divers could exchange mouthpieces in narrow caves; Ted Eldred's single-hose Porpoise had been on sale since 1952.

No published history of the octopus was found during research. The only other account is a discussion thread on the ScubaBoard forum, seen as a search summary, which asks whether Exley or Butch Hendrick was first, suggests that NASDS (the National Association of Scuba Diving Schools) may have been the first recreational agency to require a backup second stage, and credits Hal Watts with mounting it on a swivel. None of that comes from a published source, and we could not confirm any of it.

A search summary of a Scuba Diving magazine article says alternate air source training was not mandatory in all PADI courses until September 1986. The article itself could not be opened, so that date is unconfirmed.

Today's buoyancy compensators are covered on BCDs; regulators, including alternate second stages, are on regulators. Exley's wider influence on cave diving is on cave and technical diving.