SUN OVER THE YARDARM - origin

For many years, from the First World War (1914 - 1918), English public houses, pubs, could not open their doors to ply their trade until 11:00 a.m. in order to ensure that essential industry workers turned up each morning to manufacture weapons and munitions. All English 'pubs' then had to close again at 15:00 each day before opening again at 19:00 until 11:00 (different, more stringent, hours applied on Sundays) much to the bemusement of visitors from abroad during the summer months who wished to quench their thirsts. Restrictions which were not lifted until the late 1980's.
'Over the Yard-arm', still applies, socially and is a good yard-stick to sensible consumption of aqua fortis!

It is 11am, first morning break.
Officers had access to Rum, Wine and Brandy generally
Senior sailors could have their tots neat not as Grog
Drinking water was not at option at sea.
They did carry Ale which was a good substitute.

The 'arm' is only the end of the yard and usually painted white and outboard of the lifts. But to be pedantic not all yards have arms! To be strictly accurate only vessels that set stunsails had arms because the ends were markedly longer than yer common square rigger's yard.
And I didn't answer the security question incorrectly when I said the colour of the sea is grey!! It is in my neck of the woods.

Officers didn't drink rum. That was for the jack tars.

I am an alcoholic, I try to wait until the sun has at least risen - mind you most days I do not get up until noon so I feel justified in driving immediately to the pub.

All this time I thought I had to wait until after 4:00 pm!!

Bet life's a bundle of laughs in your house Tom.

Blimey, the discussion still going on... It would appear that the whole "Over the Yard Arm" thing is an old naval joke, the condition always pertains, like "So long as your A### points down" it means it is always appropriate to have a rum. In modern language we seem to have lost the knowledge which gives lie to the phrase, so it has come to mean a real time, assumed to be in the early evening as the sun is sinking over a mythical "yard arm", when in polite society, it becomes acceptable to "open the brandy darling".

It is interesting to hear how early in the day the sun can be considered to be over the yardarm. It is also a bit disappointing. Half past ten (I hate the sloppy "half ten") is very early. I like to think I am exercising some self-restraint by waiting till, say, 6 p.m. to have a drink.However, I like the expression as it seems to mean whatever time of day you want it to,so I will stick with it.

My father said if you got into the right spot aboard, the sun would be over the yardarm - if there were sun, and it weren't just rising or setting... So, it was always time to start drinking. The sea is sewage-coloured at Spithead, by the way.

The first sailors crossing the Atlantic would have all sailed east to west. Therefore, with lengthy crossings, the saying would have been developed and continued its usage, even once the aspects of it no longer made logical sense...

My Uncle Charlie was a windjammer captain and sailed mostly the Atlantice between London and Rio.. I remember him telling me that when he "graduated " from a cabin boy to an officer he took his first shot of undiluted rum around noon every day thereafter !

@Ted Vandebint

The OP was absolutely correct while you, kind sir, are out of your depth.