1-Carb­oxy­naphthalen-2-yl acetate monohydrate

In the title compound, C₁₃H₁₀O₄·H₂O, both the carboxylic acid [C_ar-C_ar-C-O = -121.1 (2)°, where ar = aromatic] and the ester [C_ar-C_ar-O-C = -104.4 (3)°] groups lie out of the mean plane of the conjugated aromatic system. In the crystal, the organic mol­ecule is hydrogen bonded to water mol­ecules through the ester and carb­oxy moieties, forming chains along the a-axis direction. The methyl H atoms of the acet­oxy group are disordered over two equally occupied sites.