Below is an context that describes a sql query, paired with an question that provides further information. Write an answer that appropriately completes the request.  # noqa: E501
### Context:
CREATE TABLE table_18946749_4 (col__m_ INTEGER, island VARCHAR)
### Question:
What is the highest value for col(m) at North Island?
### Answer:
SELECT MAX(col__m_) FROM table_18946749_4 WHERE island = "North island"