One of the acronyms picked along the way was ABL (Another B!@@$y Lock).
The first lock after Budapest was exciting but the novelty soon wore off, especially when you go through them at night.
The first lock, Gabcikovo, was quite large and could easily fit two vessels side by side
As the journey continued the locks got narrower so the occasional bump in the night was not uncommon 
Overall there are around 68 Locks to traverse. This is necessary due to the varying level of the rivers. Between Budapest and Passau you traverse 206m in altitude and between Passau and Vienna you traverse another 103m. By time you get to Amsterdam you have dropped back down and are 5m below sea level.
