Concerning KUROITA's theory, in recent years objections to it have surfaced; in 1990 the maritime historian Dr. Shozo KANASASHI ran a computer analysis of the tides on the day of the battle, and concluded that there was a neap tide that day, and thus that there could not have been a strong, swift current of eight knots, and moreover pointed out that the tidal study done in the Taisho period had been conducted at the narrowest point of the Kanmon straits (where it would have been impossible for more than 1000 ships to fight), concluding that in the spacious area of sea near Kanju and Manju islands, the tide was under one knot in speed and would have had no influence over the course of the battle.
この黒板説については、近年になって反論が出され、海事史の金指正三博士は1990年に潮流のコンピュータ解析を行い、合戦の行われた日は小潮流の時期で、8ノットという早い潮流は無く、また大正時代に潮流を調査した場所は最も狭い早鞆瀬戸であり（ここで千艘以上の兵船で戦うことは不可能）、広い干珠島、満珠島辺りの海域では潮流は1ノット以下であり合戦に影響を与えるものではないとした。