This does work, I tried it the other day as a simple way of doing it but did not post it in the end
It looked like physics is being used too much, jumpy and not smooth.
The action of the wave going from left to right will force the boat up and down but If you do not get the side bars correct the boat will tip and roll, this also will happen if the "waves" are catchy.
As suggested above. (I think )
I would convert the text image to a vector object.
Edit the vector so the top clings to the top of the letters in a wave form.
Select all the anchors.
Select the Boat group and give it a motion path.
Select its motion path and then paste the vector path to that.
That should give the motion path the same wave form.
Then look at @MaxZieb Hype Dynamic Camera which I think will help keep the boat centred as it goes through its motion.