Remember that missing bollard I mentioned a couple of days ago? By the time I'd found some vaguely circular dowel, reduced it by hand to something more circular and the correct diameter, drilled a hole for the upper part (1mm wire), primed and painted it, I must have spent about two hours on it. Still it looked a good match for the other one, so I put it to one side for the paint to dry properly and started fiddling around inside the hull. Various flakes of paint, etc. in there, so turned it upside down and gave it a shake. Good shower of paint flakes, wood chips and then a quiet thump as something slightly heavier fell out from the bows.
Yep, it was the missing bollard, now reattached. At least I now have a spare!