Matsuyama to Hiroshima by jetfoil

I'm thinking we'll take the jetfoil from Matsuyama to Hiroshima to avoid the long train trip via Okayama, and also because it looks like fun. Our trip will be in the second half of April.

My plan is to book the day before if the weather looks good-I would prefer to do the trip by train if the alternative is the car ferry. My question is, if it's too rough for the jetfoil, do passengers get moved to the vehicle ferry?

I did the same trip but from Hiroshima to Matsuyama two years ago in early to mid-April without any trouble. The passenger ferry was almost empty and the trip was very smooth as I recall.