A method to utilize a chemical genus of chromen-4-one derivatives as non-toxic, environment friendly antifouling agent, a coating material for objects submerged under the water and subject to biofouling based on the chromen-4-one compounds, as well as a method of obtaining one of such chromen-4-one antifouling compounds, 4′,5,7-trihydroxy-isoflavone, from a natural source. Particularly exemplary of such substituted chromen-4-one antifouling compounds are provided and they are 4′,5,7 -trihydroxy-isoflavone, 4′,5-dihydroxy-3,6,7,8 tetramethoxy-flavone, 3′,5-dihydroxy-3,4′,6,8 tetramethoxy-flavone, 4′,5-dihydroxy-3,6,7-trimethoxy-flavone, 4′,5,7-trihydroxy-flavone, 3′,4′,6,7-tetrahydroxy-flavone, and 5-monohydroxy-flavone.