The JIS anchor, i.e., Stockless A-type anchor, hereinafter JIS-type anchor, is one of the most popular used anchors in Japan and is equipped on many ships. In order to prevent anchoring accidents, the holding ability of the JIS-type anchor must be clarified with respect to detailed seafloor sediment components. Therefore, the seafloor sediments were herein classified into six categories based on their particle size in the nautical chart and divided into seven groups. First, we built an sediment map around Japan’s coastal area using these seven groups. Second, using a JIS-type anchor, the maximum holding coefficient was studied for two towing speeds (0.18 and 0.02 kt) and six towing angles (every 5° from 10° to 30°). The maximum holding coefficient was achieved when the sediment group was “fS M” (“SM” in the nautical chart). However, the holding coefficient became half when the sediment group was “M Cy” (“M” in the nautical chart). Furthermore, the maximum holding coefficient was obtained when the towing speed or angle was 0.18 kt or 10°, respectively.
