Under the IALA-A Buoyage System, a green spar buoy with a triangular topmark would indicate that the buoy __________.

Correct Answer: Option B — should be left to port when heading out to sea

In the IALA-A system, green buoys are left to port when returning from sea (entering port). A green spar buoy with a triangular topmark is a lateral mark. Following the 'Red Right Returning' convention for IALA-B, IALA-A reverses this, requiring the green buoy to be kept to port when heading toward land.