Please help w/ Flex modifier of plane to make water

[JBEDsol]

I'm trying to follow this tutorial to make a boat in water. 

https://www.youtube.com/watch?v=wuJxRWHQCcg

However the edges of the plane act completely differently than in the tutorial and I can't figure out what I'm doing wrong.  Any advice?

[RobH2]

I'm self-taught in Max and have done 1000s of tutorials. It's not uncommon for me to do them twice or three times when things don't seem to work. Sometimes in the 2nd or 3rd try you'll see a setting you missed or one that didn't hold. I'd go through it again. Also, frequently the tutorials are from older versions of Max. Sometimes the new versions behave a little differently. You'll need to keep that in mind and may have to make some adjustments. Lastly, other people my have had issues like you. I always read the comments (if there are any) below the tutorial to see if anyone asks the question and there is an answer. 

[Anonymous]

Unfortunately, 8 of 10 tutorials didn't work for me, I always search more information.
About your question, I can't open your file, I got  error popup message, kinda it's broken