One thing NASA discovered way back during the Gemini program in the 1960's was how useful putting handles and handrails on everything is when you don't have stable gravity to hold you and things in place. It was only on the final Gemini flight that they put it all together and Buzz Aldrin (a hero of mine) was able to conduct the first truly successful EVA. He had lots of handles and rails (and places to put his feet) to hook onto and to grip. On all the previous space walks, the astronauts came literal close to death whenever they tried to do anything. Dangerously high pulse rates and blood pressure whenever they tried to move themselves to use any tools. Having something to hold onto made all the difference in the world. (Or all the difference out of this world!)
The same thing applies on any unstable mode of transportation, including trains on bumpy tracks, buses and boats. I've noticed the lack of places to grab in many of the older coaches and in the aisles in the sleepers. I hope the new VL2's and Amfleet replacements have many more of them, and when they refurbish the old Viewliners and Superliner, they add them wherever possible. It's pretty cheap and great for people with ordinary mobility, let alone mobility-impaired people.
The only time I've ever been sea-sick was on one of the older Boston-Provincetown ferries. It was the first trip after a storm the night before. The first 3rd (about half an hour) was fine as we sailed past the harbor islands to the entry to the harbor. Then the middle third was very rough until we got into the shelter of Cape Cod. I had missed lunch and got a snack, a bagel and a cup of coffee, from the snack bar. I had almost made it back to my seat, balancing the bagel on top of the coffee cup with one hand and trying to hold onto the seats of other passengers with the other, when we hit the open water and my bagel went flying! Most of the very hot coffee sloshed out onto my hand and the floor. (Why they didn't have lids, I don't know...) A few seconds later, I was too sick to eat or drink anyway. It got a little better when we reached the smoother water near P-Town, but I was still woozie. Then, 5 minutes ashore, I was totally fine, and my friends who picked me up there took me straight to Moby ****'s in Wellfleet for a terrific, enormous sea food late lunch/early dinner. (I know it's an AU requirement to always discuss food whenever possible.)
I've ridden other. newer B-P (and other) ferries since and noticed the seats usually have handles in the upper corners of their backs, which I now truly appreciate. I hope the new Amtrak coaches, diners and observation cars have the same. (I took a train once or twice with a new VL2 diner (being used as a sleeper lounge), but didn't notice whether it had hand-holds on the seats or partitions.)