Theodore William `` Ted '' Lange ( ; born January 5 , 1948 ) is an American actor , director , and screenwriter best known for his role as the bartender , Isaac Washington , in the 1970s TV series `` The Love Boat '' .
Theodore William `` Ted '' Lange ( born January 5 , 1948 ) is an American actor , director , producer , and screenwriter . He is best known for his role as the bartender , Isaac Washington , in the 1970s TV series `` The Love Boat '' .