Plastic bags are meant to discourage boobies from landing on the masthead.
Apparently they don't work. On the NOAA Ship McARTHUR
during STAR 2000 operations in the Eastern Tropical Pacific Ocean.
Image ID: ship0496, NOAA's Fleet Then and Now - Sailing for Science Collection
Location: Eastern Tropical Pacific
Photo Date: 2000 Fall
Photographer: Shannon Rankin, NMFS, SWFSC
• High Resolution Photo Available