Theme: Nurikabe Time. Don’t wait for the 13th hour to figure out where all the clock islands go.
Answer String: Enter the length in cells of each of the black segments (the unnumbered, connected “ocean”) from left-to-right for the marked rows, starting at the top. Separate each row entry from the next with a comma.
Time Standard: Nurikabe Master = 3:00, Expert = 9:00, Novice = 30:00
Note: Advice on solving this puzzle has now been posted in “Ask Dr. Sudoku #2“