Might I point out to you that the USS Nevada had NOT dropped either it's original compliment of anchors nor two extra ones that my original ATL scenario posting added to the Tatuta Maru as she was being modified into a blockship. Neither did the USS Nevada have her bottoms blown out by carefully considered and placed demolition charges designed to send her quickly down the only 12' between her bottoms and that channel base coral. If you were to conduct a bit of research you would find that the guns carried by the Antares and the two minesweeepers (Condor and Crossbill ?) were but tiny popguns when compared to a 17,000 ton cargo-liner fitted with some 6" guns of her own. Neither were any of the minesweeers actually tugboats fitted with engines powerfull enough to push a resisting 17,000 ton opponent anywhere. My ATL Tatuta Maru would only be at any risk of being knocked out of her proper blocking position if a US battleship should ram her on it's way out of the harbor, before she was properly settled the 12' down. Not a likely event on a peacetime Sunday morning according to Japan's Honolulu Consulate ship movement reports to Tokyo. Even if such were to happen, the combination of Kido Butai warplane inflicted damages and IJN minisub torpedos might succeed in sinking the battleship in the entrance channel anyway. AFAIK only 1 minisub had a faulty gyro-compass and although the crew tried hard, didn't get into Pearl Harbor because of it. All 5 of my ATL minisubs would not have to thread the PH entrance channel IN THE DARK for one thing. They would be tracking the American gateguard DD on it's well known regular "patrol box", in daylight. Much easier.[/QUOTE] Sailing in daylight or darkness wouldn't matter. The submarines still got lost in transit. Only one of those submarines were found to have fired any torpedoes. The remainder still had them aboard when they were finally found, days, months or years later. It doesn't matter if you are talking ATL or OTL here, those same midget subs will still get lost, either one way or another and you'll have two or less of them off the harbor mouth and if they are raising their periscopes to line up for a torpedo shot, or just to get their bearings, they will most likely broach, which will plainly be seen either by the lookouts or the crewmen of the Ward. If the maru unmasks her 6" guns and fires at the oncoming US ships, the Army forts will return fire with their ready service ammunition. Put a few rounds into the bridge or boiler room and the unarmored maru's speed quickly becomes zero, or it runs aground well short of the harbor mouth.