[Rosie] Well, it's a cheap drink. No charge for bitters or soda, normally. When my dad was in the Royal Navy, it was traditional for midshipmen, and some other low-ranking officers, to drink pink gin, as all you paid for was the gin - hence it was the cheapest drink in the Officers' Mess - because midshipmen were so lowly paid.
(Phil) Didn't they have grog? Maybe not often enough. When I was a student we only drank spirits if we were deliberately trying to get as pissed as possible because in those days a shot of spirits was nearly twice the price of a pint of beer. In today's money I'd estimate the prices as £2 and £3.50.
When I was at Uni (mid-late 90s) my University Union used to do a happy hour. 50p a pint (the usual price at the time in a pub was £1-£1.25 depending on the brand). At about quarter to seven you'd see the bar packed with students buying 4 or 6 pints at a time. They would take them back to their table and drink them over the next couple of hours. You might think that the beer tasted awful after sitting in a glass for over an hour, and you'd be right. But it was cheap.
[Rosie] Yes, they did have rum until July 1970 (one eighth of a pint per day), which I think was issued as two-water grog (watered-down 2 parts water to 1 part rum). Pusser's Rum has been made since about 1980 to the old Admiralty recipe and a donation goes to the Royal Navy Sailor's Fund from every bottle sold. I have some of the blue label, bottled at 54%abv, and it's quite a fierce nip if you don't water it down at all. However, when the officers gathered for a social in their mess, the poor midshipmen (officer cadets, essentially) would have to join in, and behave like an officer, while on a phenomenally meagre wage, hence the most popular cheap, "sophisticated" drink for them (i.e. not neat spirits or beer) was pink gin.