On Sat, 12 Jun 2021 17:58:19 +0100, The Natural Philosopher wrote:

On 12/06/2021 17:13, Commander Kinsey wrote:
Why do people say left hand down instead of left? We all know which way
to turn the wheel to make the car go left, and it's the same in reverse.
And if I'm reversing looking over my shoulder, one hand isn't on the
wheel so the phrase makes no sense!

I take it you have never steered a boat with a tiller

Why would that matter? Unless the person operating the boat didn't know how to steer a boat, you're just telling them to move the boat left.