According to the British Post Interrogation report derived from the interrogation of Bismarck's survivors, the entry hole in the bow was plugged and the exit hole had a steel plate welded over it from the inside, by a diver working in the flooded compartment. This will have been a permanent repair and would have restored the ship to full operational efficiency. The only reason for Bismarck's reduced top speed was the possibility of structural damage occurring due to the weight of water in the bow.
Until this time, it had been thought that the hole had simply been temporarily patched using a collision mat, which was torn away during violent maneuvering during the evening of the 24th. This permanent repair using steel plate will have probably been carried out during the afternoon of the 25th. The forenoon being unsuitable for such work, with the ship making high speed in order to put distance between herself and her erstwhile shadowers.
Although there is no actual mention in the Interrogation Report, of a permanent repair to the hole in the port side, I can seen no reason why that hole should not have been permanently repaired also. Perhaps as the urgency of the situation had dissipated with the most difficult repair being completed, patching the other hole went unremarked.
From what has been said in earlier posts, I doubt that we shall ever be able to correctly identify those two holes, though we can say for certain that the "exit hole" shown in the dive photos was incurred on the morning of the 27th, not on the 24th.
The Holes In Bismarck's Bow
Moderator: Bill Jurens