We also have a peanut alg kid, no matter how many times you tell people, they still do stupid stuff like bringing along peanut butter cookies and it's "oh, I forgot, we'll just put these over here...t". Or peanut containing desert and "we'll just use a different spoon for that..."
My did had to go to the ER for his whole face swelling and couldn't breathe after a kid at school flicked a peanut across the cafeteria and it just glanced off his face.
Oh, I forgot I was pointing a loaded gun at -your- child next time I'm at the range....
Serious allergy is nothing to play with, and you'd likely have a dead kid by the time you got to the dock if you had no ability to treat. Keep an epipen available for that kind of alergy. Bee allergy is different, in that this person has never had a significant reaction, but that doesn't mean the next one won't be. It's his responsibility to keep a pen with him and personally I'd want to see one before he was on my boat.