An orange, rod-shaped, gliding bacterium, designated strain CBA3208T, was isolated from sea water of Jeju Island, Republic of Korea. Cells were observed to be Gram-stain negative, strictly aerobic, catalase positive and oxidase negative and to hydrolyse starch, gelatin, and Tweens 40 and 80. The major fatty acids were identified as iso-C15:0, iso-C17:0 3-OH, and iso-C15:1 G. The only isoprenoid quinone was found to be menaquinone-6 (MK-6) and the major polar lipids were identified as phosphatidylethanolamine, two aminolipids and four unidentified polar lipids. The DNA G+C content of strain CBA3208T was determined to be 34.9 mol%. Strain CBA3208T is considered to represent a novel species of the genus Aquimarina, for which the name Aquimarina seongsanensis sp. nov. is proposed based on this polyphasic taxonomic analysis. The type strain is CBA3208T (=KACC 17667T =JCM 19529T).