Theme: It ALL Adds Up (as shown below, the author intended all clues to be part of arithmetic groups)
Author/Opus: This is the 2nd puzzle from guest contributor Izak Bulten.
Rules: Standard Nurikabe rules.
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. Separate each row’s entry from the next with a comma.
Time Standards (highlight to view): Grandmaster = 1:30, Master = 2:30, Expert = 5:00