Year Vessel Date Longitude (°E) Latitude (°N) n  
2016 Shunyo-Maru Jul 24–Aug 05 133°28'–138°20' 35°45'–38°44' 68  
    Dai-Go Kaiyo-Maru Sep 03–Sep 13 137°04'–139°04' 37°34'–40°34' 20 SI-line
 
2017 Mizuho-Maru Apr 21–Apr 24 135°20'–137°20' 35°40'–37°40' 7  
 
2018 Shunyo-Maru Jul 24–Aug 01 133°30'–138°15' 36°00'–39°35' 24  
Hokko-Maru Aug 30–Sep 08 136°45'–139°02' 37°35'–40°20' 48 SI-line
 
2019 Hokko-Maru Feb 25–Feb 25 137°35'–138°14' 38°08'–39°05' 3 SI-line
Shunyo-Maru Apr 15–Apr 17 136°20'–138°14' 38°08'–41°00' 3 SI-line
Yoko-Maru May 23–May 25 135°20'–137°20' 35°50'–37°20' 6  
Tenyo-Maru Jun 18–Jun 20 136°20'–138°13' 38°08'–41°00' 6 SI-line
Shunyo-Maru Jul 13–Jul 28 133°30'–138°15' 35°45'–39°35' 42  
Hokko-Maru Aug 30–Sep 08 136°49'–138°55' 37°20'–40°22' 46 SI-line
Tenyo-Maru Sep 20–Sep 21 136°20'–138°14' 38°08'–41°00' 6 SI-line
 
2020 Hokko-Maru Feb 21–Feb 25 136°21'–138°14' 38°08'–41°00' 6 SI-line
Shunyo-Maru Apr 12–Apr 14 136°20'–138°13' 38°08'–41°00' 6 SI-line
Yoko-Maru May 24–May 27 135°35'–138°00' 35°40'–37°30' 14  
Tenyo-Maru Jun 15–Jun 17 136°20'–138°13' 38°08'–41°00' 6 SI-line
Jul 15–Jul 27 138°06'–139°50' 37°17'–39°55' 21  
Yoko-Maru Aug 01–Aug 09 131°15'–135°45' 35°00'–37°45' 26  
Hokko-Maru Aug 29–Sep 08 136°05'–139°25' 37°36'–40°38' 92 SI-line
Tenyo-Maru Sep 22–Sep 23 136°20'–137°35' 39°05'–41°00' 4 SI-line
 
2021 Hokko-Maru Feb 22–Feb 23 136°20'–138°14' 38°08'–41°00' 6 SI-line
Shunyo-Maru Apr 16–Apr 17 136°20'–138°14' 38°08'–41°00' 3 SI-line
Yoko-Maru May 21–May 24 135°50'–138°00' 36°00'–37°40' 8  
Tenyo-Maru Jun 11–Jun 13 136°21'–138°14' 38°08'–41°00' 3 SI-line
Yoko-Maru Jul 14–Jul 19 133°30'–135°00' 35°45'–37°45' 16  
Tenyo-Maru Jul 17–Jul 24 138°46'–139°50' 38°16'–39°58' 32  
 
Figure