Not sure what happened here: no furore, no splash, just the arrival through the cat flap of Sir, wet from tummy to tail while his head and and front paws were dry. He’d been sitting on the edge of the well deck earlier, peering intently into the undergrowth on the shore, which also rather hid the gap between boat and land.
We rather suspect he’d been “stalking” a small furry animal or something, then pounced and found thin air under his rear end. Since then he seems to be fine, but has been walking around with his tail held very low, as though reluctant to move it. Nothing obvious to the touch (and no complaints at an examination): maybe he’s pulled a another muscle or something. He’s not getting the hang of this aquatic existence!