Sergeant Rachael Robinson, 37, was repeatedly smashed against the deck of a French fishing vessel as she dangled from a Sea King on March 21.
For 30 minutes, Sgt Robinson attempted to disconnect her wire and board the vessel, 50 nautical miles west of Milford Haven, west Wales, only for it to pitch violently and roll 40ft, repeatedly pummelling her.
"It was like running into a wall," she said.
A Portuguese crew member had smashed his head open on a door in the horrendous conditions and needed urgent medical attention.
Her citation said that despite the great pain she suffered in the operation, Sgt Robinson "never once gave up".
She is due to receive her medal from the Queen later this year.