Is the joke here that it would be embarrassing for the captain to forget this?
I remember being young taking my boaters safety course and having to take this section over three times. Why does left and right stop existing once you are on a floating pos?
I always remember that port and left both are the shorter word, and have the same number of letters.
My grandfather was a bomber pilot and he always remembered it by picturing himself flying north along the east coast, where all the ports would be on the left.
and even, as in even numbers.
Port, left, even…all words an even number of letters Starboard, right, odd…all words are an odd number of letters.
Also, the old name for “port” is “larboard”, which starts with an L for left.
“Red right returning”. You must be leaving port.