Redstone Booster Recovery 4
After the swimmers had attached lines to the booster, it was floated into position over the two saddles that would support it when it was not floating. It is not clear if this was done by reversing the Fort Snelling or by pulling the booster into position, but given the needed precision, one suspects the latter.
The presentation on the project's results also mentions the addition of a watertight bulkhead to the booster, but I suspect that was over the engine and is not what is pictured at the front of the booster. Photos of PGM-11 boosters under construction show a center port of similar size on top of the tank.