They were cruising for a bruising. Passengers freaked out as 40-foot waves slammed into a cruise liner navigating a treacherous stretch of ocean off Antarctica, as seen in freaky footage on Instagram.

It was the passengers aboard Quark Expeditions’ Ocean Explorer ship that felt the true wrath of the waters as they went flying about, sliding across the floors and knocking into the walls. Lesley Anne Murphy, a travel blogger on board captured the footage showing her fellow cruisers experiencing Drake Passage during a return trip from Antarctica.

Passengers aboard a luxury cruise ship had a harrowing experience as 40-foot waves battered their vessel while crossing the Drake Passage — the notorious 600-mile-wide stretch of water separating Antarctica from the southern tip of South America.