the.com/batten down the hatches

Nautical for brace yourself, because the easy part is over.

means To secure everything and prepare carefully for trouble that's clearly on its way.

from Straight from old sailing ships — 'battens' were strips of wood used to fasten tarpaulins ('hatches,' the deck openings to the hold) down tight before a storm hit, keeping water out and cargo safe. Sailors did this as the sky turned, which is why the phrase carries that specific flavor of 'the warning signs are here, now act.' It moved ashore in the 19th century as a general warning to brace for rough weather of any kind, literal or otherwise.

origin
sailors nailed wooden battens over hatch covers before storms
batten meaning
a strip of wood securing tarps against rough seas
modern use
now means prepare for any incoming disaster, wet or not
irony
people say it while doing nothing structurally useful at all
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