What does the cryptic crossword clue "He falls overboard after getting tanked up (10)" mean?

The definition is "He falls overboard after getting tanked up". The wordplay uses a cryptic definition. Cryptic definition The answer is SCUBADIVER.

He falls overboard after getting tanked up (10)

Independent Cryptic #11899 | 23 Across | 2024-11-28 flower