Transferring paid onboard activity to another person

[SLM]

Has anyone booked on onboard activity (like the Flowrider lesson) and then tried to transfer the activity to a different person in a linked group? Can you do that? Someone in our group of 10 seems to be assuming that if he decides not to do the Flowrider lesson at the last minute, someone else in the group can just go in his place, and I'm wondering if he is going to be surprised that that isn't an option. Any thoughts would be appreciated. 

[Ampurp85]

Not an option. The only way the transfer things is when cabins switch out guest as the stuff is tied to that reservation. If the person decides to not do something it will be cancelled if they do it in appropriate amount of time. This means a refund.