When Royal Caribbean decided to be the only cruise line in the world with FlowRiders installed on its cruise ships, the cruise line had to have the FlowRider designed to fit on a ship.
Unlike some surfing simulators on land with long wash-out zones (the space between the top of the ridge and the back wall) where the participant will lose speed and come safely to a rest, the FlowRiders on Royal Caribbean cruise ships have a wash-out zone of only around eleven feet. This creates a danger where the participant will crash into the back wall at high speed.
The problem is compounded by a lack of sufficient padding of the wall.
For example, watch this link and see this passenger wipe out. Although he is not a skinny fellow, he still crashes into the back wall. Watch the last few seconds and you can see his arms and legs fly into the air upon hitting the wall.
You can also get an idea of the force of the water by watching the video below.
Are these FlowRiders defectively designed? Should there be longer wash-out zones and thicker padding on the end wall?