Retired Rear Adm. Charles Herbert Andrews, 73, a heavily decorated submarine commander who was credited with sinking or damaging more than 100,000 tons of Japanese shipping during World War II, died Monday at the Pomerado Hospital in Poway, Calif. He had pneumonia.

In June 1942, Adm. Andrews, then a commander, was appointed to the USS Gurnard, a new submarine that was still being fitted out. The vessel was commissioned on Sept. 18, 1942, and Adm. Andrews sailed her into the Pacific.

During the next two years, the future admiral took the Gurnard on six war patrols. He won two Navy Crosses, the highest decoration in the service except for the Medal of Honor, and two Silver Stars. The boat and her crew were awarded a Navy Unit Commendation.

The Gurnard saw action in the Palau Islands, the South China Sea, the Philippines and elsewhere, and what it accomplished under Adm. Andrews is summarized in the citation accompanying the Navy Unit Commendation:

"Holding relentlessly to her missions in defiance of watchful aircraft patrols and surface escort vessels, the USS Gurnard daringly pierced the enemy's screen to strike at heavily protected convoys and combatant units . . . . She boldly closed range and sent her gunfire and torpedoes into one target after another despite continual hostile bombing and depth-charge attacks and sank 11 Japanese ships, including a destroyer, for a total of 71,500 tons; she damaged 10 additional vessels, one a 32,700 ton battleship and one a 17,000 ton aircraft carrier, to score a total of 107,200 tons."

Adm. Andrews won his first Navy Cross for sinking over 15,000 tons of shipping and damaging over 43,000 tons in Japanese-controlled waters. His second Navy Cross came during a patrol in which he sank three freighters and a large tanker and damaged a battleship and another freighter. He left the Gurnard in September 1944.

His subsequent war service included a staff assignement in Hawaii, during which he earned a Bronze Star.

In the postwar years, Adm. Andrews commanded a submarine division and later a destroyer flotilla. He also graduated from the Naval War College. At the time of his retirement in 1959, he was an antisubmarine warfare officer on the staff of the chief of naval operations.

Adm. Andrews was born in New Haven, Conn. He graduated from the U.S. Naval Academy at Annapolis in 1930. He joined the submarine service in the 1930s.

After he retired from the Navy, he moved to Encino, Calif., and was an executive of the Lockheed Aircraft Corporation until 1973. Since then, he had lived in Rancho Bernardo, near San Diego, Calif., and in York Harbor, Maine.

Survivors include his wife, Eleanor, of Rancho Bernardo and York Harbor; two sons, Charles H. Jr., of York, Maine, and Michael K., of Poway, Calif.; three daughters, Nancy Frost of McLean, Donna MacKenzie Renard of Norfolk, and Sarah Andrews-Collier of Portland, Ore.; three sisters, Marie Reynolds of Madison, Conn., Celia Heiser of Winter Park, Fla., and Doris Abbatello of Hamden, Conn., and 12 grandchildren.

The family suggests that expressions of sympathy be in the form of contributions to the American Heart Association.