RFA Tidespring's crew toasted crossing the equator and entering the southern hemisphere – producing some breath-taking pictures in the process.
Commodore David Eagles allowed the ship's chaplain to be at the helm as they made the crossing.
It was all smiles on deck and, in a tweet, RFA Tidespring said: "CSG21 and whole ship sundowners with Pimm's to mark the occasion."
The Royal Navy sea vessel has been deployed to support the UK-led Carrier Strike Group (CSG21), which recently passed the midway point of its deployment.
RFA Tidespring is part of the Royal Fleet Auxiliary (RFA) that delivers worldwide logistic and operational support to Royal Navy operations. They are the uniformed civilian branch of the naval service staffed by UK merchant sailors.
The ship also "had the honor and privilege" in undertaking a RAS (replenishment at sea) with JS Shiranui from the Japanese Maritime Self-Defense Force.
RFA Tidespring tweeted: "It has been such a pleasure to operate with ships of the Japan MOD (Japan Ministry of Defense) again.
"We look forward to more of it in the future."