Sea-surface and mid-water trawls, to which a small submarine bathythermograph system (SBT) was attached, were carried out from August 1 to 4, 2015, in inshore areas off Mishima island, Hagi, Yamagushi Prefecture, by the training vessel “Tenyomaru” of National Fisheries University (voyage 232). The numbers of species caught at four research stations (St. 1-4) were 7 (76.1 kg in catch amount), 4 (69.2 kg), 11 (168.5 kg), and 10 (52.7 kg), respectively. Diversity indices of fishes caught at each station, as measured by taxonomic distinctness (Δ^+), were 0.79, 0.89, 0.74, and 0.79, respectively. There was no critical difference in water conditions, such as water temperature, salinity, and dissolved oxygen with conductivity-temperature-depth (CTD) measurements among the four research stations. However, the SBT record indicated that the mouth of the net was not sufficiently open at St. 2, causing a difference in the diversity of fishes caught between St. 2 and other stations.