drought ?

have we (the uk) ever put a man in the moon?

Yes, Winn, it can happen, and to a big range of different sorts of vessels.  Anything with a flat bottom is most vulnerable to this happening, . . from the smallest of today's narrow canal boats to large commercials.

Having this happen is in fact top of the list of potential serious hazards to pleasure craft venturing into the Humber, the lower Trent and the Ouse.  If they happen to ground and dry out over the low water period where the river bed is nothing but soft mud, then come Flood (tide) the suction generated by the flat bottomed boat in the soft mud can be sufficient to hold the boat down long enough for it to be swamped by the rising tide before the suction breaks and allows it to float off.

Boatmen (bargemen) in the Hull trade, working up the Trent to Lincoln and Nottingham, or up the Ouse to Goole, Selby and York used to refer to it as "sucking in", . . . but it was never as much fun as it sounds !

Keith my mate who worked the boats all over Yorkshire has said the same, worse a lot of boatmen couldnt swim! Keith said with the covers on tight and the chocks in the boat should float eventually, not something I would like to experience

It happened to 'Gilgie' the first day she moored alongside 'Platypus' in Workhouse Dock, at Brentford. It was only saved from being swamped altogether because she was lashed tightly to Platypus, which literally pulled her up from the mud - but not before water began pouring in over the bows and into the cabin. It was a dramatic moment when it happened; Platypus lurching and rocking like crazy as the Gilgie shot up dramatically once released from the mud. I only realised what had happened when I went outside to ascertain a cause for the drama.

I had read about it, but never seen let alone experienced it, but at least I remembered reading that boats on the Thames used to run ropes under the hull, so that when the tide came in they could saw the rope back & forth to let water under the hull - and that is what I did before dashing overseas and leaving instructions for a very shaken owner. There was a lot of pumping out and cleaning up to do; another minute or so and she would have been filled and possibly dragging Platypus with her.

I heard or read somewhere that sometimes people would run large diameter ropes under the boat to encourage water to get into the mud and prevent the suction issue from occurring.

Someone will say this is bollocks.

I believe it .

I don't read your posts fully any more as I find them too cerebrally challenging because you always introduce new vocabulary and on a day like this I like a simple life.

I skimmed the thread

Guilty as charged Sir - where's the plank for me to walk ?