  OPR-L304-KR-99 (H-10962): PACIFIC HYDROGRAPHIC BRANCH DANGER TO NAVIGATION REPORT.  UNCHARTED ROCK WAS FOUND, DURING SURVEY, 270 FEET SOUTHEAST OF RED ROCK ISLAND.  MULTIBEAM SONAR DETECTED THE LEAST DEPTH AS 9.5 FEET AT MLLW.  ROCK IS CHARTED AS HAVIN