What does the cryptic crossword clue "Died in helping in Canadian sea hazard? (4,3)" mean?

The wordplay uses a deletion. OB (synonym="short for obiit, died") in SLICE (synonym="helping") = SLOBICE The answer is SLOBICE.

Died in helping in Canadian sea hazard? (4,3)

Guardian Cryptic #29317 | 12 Across | 2024-02-28 flower