According to the tradition of the Ogawa family, Seisuke OGAWA used all his abilities of stonemason in building the Mikomotoshima Lighthouse on Mikomoto-jima Island, about eleven kilometers from Shimoda Port.
なお、小川家の伝承によれば、小川清助は下田港の沖、11kmに浮かぶ神子元島に神子元島灯台を建造する際、石工として腕を振るったと言う。