Hombre prevenido vale por dos / Ponerse el huarache antes de la espinada

Google images, «Batten down the hatches»

Meaning:

We batten down the hatches when we get ready for trouble or prepared for an emergency. A similar expression is “To be on your guard”.

Google images, «Batten down the hatches»

Origin:

This is a nautical expression coming form the 1800’s. When there was a storm, sailors got ready to confront it by nailing pieces of canvas and wood (battens) all over the hatches (entrance ways to the cargo  area below deck) of their ships in order to protect both the ships and their precious merchandise and belongings. Nowadays, people do the same when they protect the windows of their houses to get protected from an oncoming hurricane.

Google images, «Batten down the hatches»

Example:

Google images, «Batten down the hatches»