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Rum came aboard after 1655 and was watered from 1740
A pint of rum was the usual ration from around 1655
Royal Museums Greenwich dates a pint of rum as the sailor’s usual daily ration from around 1655, served half at noon and half at about five or six in the evening.
Vernon’s order of 1740 gave the word grog
Royal Museums Greenwich records that in 1740 Admiral Edward Vernon ordered his men’s rum diluted with water and lemon juice. Wikipedia, a secondary source, dates the order to 21 August 1740, when Vernon commanded in the West Indies, and its rum ration entry gives the mix as half a pint of rum to a quart of water.
By the same account Vernon wore a coat of grogram cloth and was nicknamed Old Grog, and the watered rum took the name. The order as Wikipedia quotes it leaves the men to buy sugar and limes from their savings to make it more palatable, where the museum’s catalogue speaks of lemon juice.
By 1970 the tot was one eighth of a pint
By 1970 the tot was one eighth of a pint of rum, about 71ml, as Hansard’s record of that year’s Commons debate shows.
The tot as described in the Commons in 1970, from Hansard
Volume
- Figure
- One eighth of an imperial pint, about 71ml
Senior rates
- Figure
- Neat
Junior ratings
- Figure
- With two parts water, as grog
Age to draw it
- Figure
- 20 and over
Equivalent given in 1970
- Figure
- Slightly more than four single whiskies
| Measure | Figure |
|---|---|
| Volume | One eighth of an imperial pint, about 71ml |
| Senior rates | Neat |
| Junior ratings | With two parts water, as grog |
| Age to draw it | 20 and over |
| Equivalent given in 1970 | Slightly more than four single whiskies |
Senior rates drew their tot neat. Junior ratings had it mixed with two parts of water. In the Commons in 1970 the minister described the issue as “the equivalent of slightly more than four single whiskies”. Sailors under 20 were not entitled to it.
The Admiralty Board ended the tot on grounds of efficiency
On 17 December 1969, in a written answer to the MP Christopher Mayhew, the Admiralty Board said the rum issue was “no longer compatible with the high standards of efficiency required” now that sailors’ tasks were “concerned with complex, and often delicate, machinery and systems”.
The House of Commons debated the decision on the evening of 28 January 1970. James Wellbeloved, MP for Erith and Crayford, opened for the tot. Dr David Owen, the Under-Secretary of State for the Royal Navy, answered. He cited a survey at the British Military Hospital in Singapore that suggested the navy had three times the Army’s rate of alcoholic casualties, and said fewer than 30% of junior ratings still drew the tot. The House did not divide.
Wellbeloved gave 1 August 1970 as the date of abolition, which made 31 July the last day of issue. The £2.7 million the navy expected to save was paid into the Sailors’ Fund, for the benefit of the men losing the ration. The full debate is in Hansard.
Black Tot Day is marked with one measured tot
Black Tot Day falls on 31 July every year. Nothing official marks it. Most people who keep it pour one measured tot, at 11am or midday, neat as the senior rates had it or with two parts of water as the junior ratings did.
A navy-strength rum makes the strength literal, so keep the measure small. A 25ml pour at 55% ABV is about 1.4 UK units.
For a drink, the Navy Grog is rum with lime and water, the line that runs back to Vernon’s order. A Rum Punch serves the same idea to a table.
Jerry Can Spirits was founded on Black Tot Day
Jerry Can Spirits was founded on 31 July 2025, Black Tot Day, by Royal Signals veterans. The date was chosen for the tradition.
Its first expression, Expedition Spiced Rum, followed in April 2026. It is a spiced rum on a Caribbean rum base, macerated by our British partner distillery, bottled at 40% ABV. It is not a navy rum. 5% of profits go to military charities.
The dates come from the parliamentary record and the museums
The last tot, the hour and the 1969 decision are from Royal Museums Greenwich. The 1970 debate, the reasons given, the size of the issue and the Sailors’ Fund are from Hansard, House of Commons, 28 January 1970.
The ration from around 1655 is from Royal Museums Greenwich, and Vernon’s order of 1740 from its catalogue entry for Admiral Vernon. The text of the order is quoted in the Wikipedia entry for grog, a secondary source.
The half pint and quart of Vernon’s mix and the Canadian and New Zealand dates are from the Wikipedia entry for the rum ration, and the orders to splice the mainbrace from its entry for splice the mainbrace, both secondary sources. The written answer of 1969 is quoted in Hansard.