Only had my rod go in once - at Rising Sun in North Yorkshire.
I left my waggler rod fishing itself whilst I packed my pole away - I turned my back for a minute, heard a noise and watched with horror as my rod was dragged off my box and into the water - I made a dive for it but it flew across the water like an Exocet. Fortunately it remained afloat and after about a minute stopped moving - the carp responsible for its early bath evidently either busting my hook-length or slipping the hook.
I had a tip rod set up, so trotted round to the opposite bank cast across the rod and pulled it in. The hook-length had indeed parted
I do now know that Acolyte carp waggler rods float perfectly horizontally - and not, as I remember from years ago, with just the handle standing proud of the water like a drunken Excalibur
One of the lads fishing one of our matches on the Tees a few years ago lost a rod to a swan
He'd wound in, left the rod on it's rest and gone to speak to Terry on the next peg. Heard a splash and somehow one of the pair of resident swans had got tangled in his rod and was busily towing it across river heading for the barrage. It disappeared towards the Thornaby bank, returning a few minutes later rodless. He never did get it back.
Seen a few pole sections go in - often three or four joined sections that have been left on rollers and a sudden gust of wind has propelled them into the water. One of our club members waded out into chest high water to retrieve his at Brafferton - it was actually remarkable just how far it had travelled underwater.
Seen loads of top-kits go in - was a regular feature during fish-ins at Blyton a lot of years ago
I retrieved one when the fish that had pulled it off the end of the pole swam the full-length of the pond before getting tangled up in my rig
We had a right carry-on sorting the resulting mess out
Simon