If he can get in and out of it ok put a PFd on him and let em take it for a spin in a pond close to shore to see if he likes it. Pretty sure he will you know what they say about the dark side you should warn him about that.[grin]
Maybe after that he should try paddling othere yaks till he finds the one he likes the best. That would be my 2nd suggestion!
I didn't do that though.