Actually, locals in the Philippines used woven wicker traps for many years
to catch Nautilus (I'm not sure if they still do so).  These traps could be
lowered to great depths without crushing, because they are open to the
surrounding water, so that the water pressure inside the trap and outside
can equalize.  An object will be crushed by water pressure only if the
interior of the object is sealed off from the outside water, preventing
equalization.  For example, an ordinary glass jar without a cover could sink
a mile into the ocean without suffering any damage, because the water
pressure inside the jar and outside are equal.  But the same jar, fitted
with an airtight cover and lowered into the ocean would eventually implode
as the pressure outside increased, while the pressure inside remained
constant.
Paul M.