Good pose! Did you get your tea? - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - I was assured that the "David Bailey" exercise was while waiting for the kettle to boil. Keel-hauling was therefore not invoked on this occasion.
Looks difficult. Does it take long, or does that depend on the abilities of the person in control. - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - If it works as it should, it takes no time at all. If it all goes pear-shaped, how long it takes is a matter of how long is a piece of string . . . A steerer without much experience will obviously take a little longer than an experience steerer but a novice could take forever. And then there's the wind. A stiff breeze can thwart the efforts of even the most experienced but on the other hand, an experienced steerer can usually use the wind to advantage and make it look effortless.
I like to watch them at Tyrely Locks near Market Drayton, as a child we explored the Bridgewater Canal on our bikes. I was there when a bridge collapsed at Dunham and the area was flooded.