no follow-up missions

You are right when you say the mission was a "one-off", but that was only in connection with that particular weapon (the bouncing bomb dropped from a height of 60 feet). 617 squadron went on to achieve great success in using subsequent bombs designed by Dr. N. Barnes Wallis - these bombs were practically the opposite of the bouncing bomb, as they were massively heavier and designed to be dropped from far greater heights. "Tallboy" and, eventually, "Grand Slam" took the individual bomb weight up to 10 tons. The height these bombs were dropped from meant that they created a "camouflet" (piercing the earth and burrowing underground at such a speed that the earth closed above the bomb) - the explosion then took the form of a small earthquake - "the hangman's drop" as described in Paul Brickhill's book, and the targets included critical transport routes for German use (railway tunnels, viaducts etc), and eventually the "Tirpitz", Germany's pocket battleship which was sunk in a Norwegian fjord.

Because each Lancaster could only carry one bomb it was essential to get it as close to the target as possible and a very complicated system of bomb aiming calculations was introduced, which meant that the aircraft had to approach the target straight and level for many miles. The big advantage though was that you didn't need a direct hit - the "earthquake" effect was just as effective when a "near miss" occurred, if not more so.