McCullough’s The Path Between the Seas: “Channel lighting was installed in 1966 and night-time transits were inaugurated.”
Encyclopedia Britannica 14th Edition (late 1930s): " A thorough system of lights and buoys makes the canal as safe to use at night as by day."
McCullough’s book says a trip thru the canal’s fresh water kills all the barnacles on each ship. The world’s ships are covered with dead barnacles? Which still stick?
Can’t comment on the canal part, but can confirm that dead barnacles do stay stuck to boat hulls long after the organism is dead. The bond is like glue or epoxy - once established, it’s not coming off until you physically knock it off (with a scraper, sander, etc). They’re not attached with say an octopus-like suction cup that releases when a muscle relaxes.
I heard they are removed periodically, in part because in large numbers they are actually a bit of a drag on the ship moving through water.
Yes, that’s a well-known necessary maintenance procedure.
During WWI, a German cruiser pulled into the British base at Diego Garcia and had her hull scraped and repainted - because the British personnel at Diego Garcia hadn’t gotten the word that there was a war going on.
https://www.usni.org/magazines/proceedings/1915/march/exploits-emden
During the first two weeks of October the Emden was rumored to be in the Makassar Strait, east of Borneo, at Padang on the Straits of Malakka and southeast of Sumatra, but in reality she seems to have been far away at Diego Garcia in the Chagos Archipelago. There she cleaned her boilers, was heeled over and had her bottom scraped and painted as far as practicable