### Clue: He worked out Scuba not British, but had energy (8)
### Answer: COUSTEAU 
 ### Explanation: Definition: He worked out Scuba
 **Anagram of**(worked) [OUT + "Scuba " **minus**(not) "b"(abbrev. for "British") **plus**(but had) E(abbrev. for "energy" in physics) ].
Answer: Jacques, French oceanographer who co-developed the Aqua-Lung, the original name of the SCUBA (self-contained underwater breathing apparatus). And of course he was a regular user of it during his work studying the sea and all forms of marine life. A WIWD (wordplay intertwined with definition) clue.