AIUI the standard of glass on these roro sea ferries was that it had to withstand a windspeed of 41 m/s.
The Hamburg one was a river boat and likely had no great safety features.
Wind and water do not carry the same amount of k/e at any given velocity. Do you know the formula to calculate kinetic energy? I knew it well within the first 5 years of my school physics education, as should you. You might want to check the densities of water and air before you comment.