Man, you were brave to take your car keys out with you! I'm affraid I would lose them overboard so I always hide them somewhere on the outside of my vehicle, under a bumper or something, so if I do break down and end up walking back to the car, at least I can go pick up the boat and/or get home.

Put the cell phone inside a couple ziplock bags, then in the box, then duct tape the box shut, then tie it to the tramp.

Do you have trapeezes on the boat yet? That's the next step, your daughter will love that!