After solving each ocean meta, teams unlocked one of Mr. Turtle's five shell pieces. The answers to the metas are written on the contiguous shell by following Mr. Turtle's rules.
The solved shell is below (the different pieces are colored to show how they fit together, constraints are shown faded behind, numbers in the upper-left corner are the number of edges darkened, path of meta answers shown in yellow highlighter).
The darkened edges form into letters that spell the answer SHIPWRECK.