A vessel should, if possible, avoid transiting the strait or entering or departing harbors on either side of the strait with a following tidal current, but if this is unavoidable vessels should not do so when the tidal current is running at full strength.
It is not safe for large vessels to transit the strait with any appreciable following current, or at SW when numerous local craft encumber the fairways.
Large vessels with sufficient power should pass through Hayatomo Seto with an adverse current of more than 2 knots and less than 4 knots; about 3.5 knots is reported to be advantageous, as by this time the possibility of meeting any ocean-going vessels proceeding in the opposite direction will be at a minimum. When a current exceeding 4 knots is running, the strait should not be attempted as strong eddies may cause a dangerous shear.
And I totally overlooked the shear effects of eddies. That could ruin your day (as in swinging the bow of a destroyer into collision course with a freighter...) :-(