I do not think that is correct Mike: international seafaring rules have ships passing port- to- port, always. Not sure how it works on, say, the Thames but in any waters likely to have ships from different countries mingling, all passing is done on 'the right' unless very specifically communicated between and agreed upon by the two ships passing, beforehand.
Even the Andrea Doria (Italian) and Stockholm (Swedish) were attempting to do that off the coast of Massachusetts, USA before things went awry.
Speaking of which: Initially, the Captain of the Andrea Doria was held most accountable for this incident but further study has led to the Commander of the Stockhold (not the Captain at the time of the collision, the third- officer had the conn.) as the prime human reason for the accident. He miss- read the radar and thought they would be passing starboard- to- starboard and made a small adjustment in the Stockholm's course to widen the distance at which they would pass; this was seen by the Capt. on the A.D. as 'crossing his bow' (correctly- they would have passed port- to- port if nothing was changed) and so altered his course also in response. The Stockholm saw this action as crossing 'her' bow and altered course more abruptly, as did the A.D. until finally the Stockholm struck the Andrea Doria close to mid-ships and at a high speed. This is where some really odd quirks come into play:
The Stockholm's bow was reinforced for ice strikes in Scandinavian waters and this 'helped' her cut nearly to the keel of the Andrea Doria. The Stockholm was at full- reverse power at the moment of the collision and would have been dragged backwards away from the impact site but her anchor lockers were destroyed and so the anchor chains and hawsers fell free and snagged on the bottom (they were in relatively shallow waters), holding her near the Andrea Doria, and after finding out she was not likely to founder, she launched all her lifeboats to assist with rescue of passengers of the Andrea Doria, which was very clearly going to sink. As with anything of such extremes, there were instances of good, bad, and just plain odd. One of the bad things was that the first lifeboats to leave the Andrea Doria contained only three of her crew; these men were later tried, found guilty and sentenced to significant prison sentences. A true oddity of the accident was a girl named Jane Morgan, on the deck of the Stockholm, who could not find her parents nor the cabin she was staying in. After some time passed, it was realized she was NOT a passenger aboard the Stockholm at all but the Andrea Doria; she had been asleep in her cabin (it was the middle of the night when the ships collided) during the collision, and thrown through the wreckage onto the deck of the Stockholm. She had relatively minor injuries, survived the accident though both her parents who were traveling with her were killed in the accident.
As it was 1956, and the ships were close to the coast of the US, rescue efforts were extremely effective, with some injured passengers being airlifted by helicopter to hospitals in the US. Overall, there was little loss of life with 46 dead, a small number considering the number of passengers being carried and the fact that the Andrea Doria capsized and sunk within hours of the collision. The Stockholm survived and in fact, was repaired and put back into service.
The Andrea Doria is 'dive- able', kinda', sorta', although it is a treacherous dive in cold water, and deep enough to require mixed gasses to reach her (I believe her keel is 240 feet down). She continues to collect deaths to this day: since her sinking, 16 divers have lost their lives diving on the wreck.
Brian
It always used to be keep left but that seems to be changing slowly.
Incidentally on the water you also pass with the oncoming vessel to your right
