Been tested?Barely 5m ASL.
However Suffolk will be saved by the Cut Off Channel (first proposed in the C15th by Dutch Engineer Cornelius Vermyuden, but not built until 1970)
I'm probably only 20 metres ASL, but I do still have my old kayaking gear in the loft. The snag is I no longer have a kayak or an open canoe.
I thought I might have time to bake one, so I bought all the eggs and flour and stuff, but it appears that you can't have your kayak and eat it........
Hope you have a snorkel and webbed feetBarely 5m ASL.
However Suffolk will be saved by the Cut Off Channel (first proposed in the C15th by Dutch Engineer Cornelius Vermyuden, but not built until 1970)
@hillwimp is going to drown at about 17m