If he's anything like me he'll remember it forever. I've got dozens of these stories with my Dad. I always learned something and didn't feel the stress he did. You just gave him a life experience.
Oh yeah, to him it was just two days on the beach...whats not to like?
And it will be a great story for him...and some street cred for me
I can hear him now "well my dad fixed our boat on the beach with nothing but a banana"
(The wrench used to pull the prop nut off does resemble a banana a bit)
Anyway, I'm pretty sure I diagnosed it right, on my first try