No, they won't let you keep it. I don't blame them for that -- there is absolutely no safe place to stow hand-baggage **inside** the cabin, except for a cargo-net arrangement that is only allowed to be used for soft items and (ahem) floaty-plane frieght in cardboard boxes.

Yahh, believe me, I have tried and tried and tried to keep my machine with me, but **everything** goes inside a special compartment in the nearside float of the plane, and they screw the lid down tight and that's that.

Enjoy the very exhilerating ride! It's fun!