NOAA Chart 18539: Columbia River Blalock Islands to McNary Dam 28.8 x 35.3 (WATERPROOF) Printed on high quality waterproof and tear-resistant material by NOAA Chart Agent, Paradise Cay Publications Paradise Cay Publications brand charts are sold exclusively by Ruby & Rudy's Books Always printed on demand using the most recent data from NOAA Prepared to be display quality. Shipped rolled in a cardboard tube.