According to the descriptions on Saiga Kassen in the second volume of "Kii no Kuni Meisho Zue" (Illustrated collection of famous places of the Kii Province), the Saiga army previously sank abatis, wooden buckets, jars and heads of spear at the bottom of the Saiga-gawa River in order to prevent the enemy's crossing of the river.
『紀伊国名所図会・巻之二・雑賀合戦』によれば、雑賀勢はあらかじめ雑賀川の底に逆茂木・桶・壺・槍先を沈めておいて渡河の妨害を図った。