Charles Darwin spent Christmas day of 1831 in Devonport awaiting favourable weather for the departure of HMS Beagle. Darwin wrote in his diary for the voyage:
Christmas day is one of great importance to the men: the whole of it has been given up to revelry, at present there is not a sober man in the ship: King is obliged to perform duty of sentry, the last one sentinel came staggering below declaring he would no longer stand sentinel on duty, whereupon he is now in irons getting sober as fast as he can. — Wherever they may be, they claim Christmas day for themselves, & this they exclusively give up to drunkedness — that sole & never failing pleasure to which a sailor always looks forward to. —
The very next day, he recorded:
My thoughts most unpleasantly occupied with the flogging of several men for offences brought on by the indulgence granted them on Christmas day. —
For 1832, in Tierra del Fuego:
This being Christmas day, all duty is suspended, the seamen look forward to it as a great gala day; & from this reason we remained at anchor. —
1833, Port Desire:
Christmas After dining in the Gun-room, the officers & almost every man in the ship went on shore. — The Captain distributed prizes to the best runners, leapers, wrestlers. — These Olympic games were very amusing; it was quite delightful to see with what school-boy eagerness the seamen enjoyed them: old men with long beards & young men without any were playing like so many children. — certainly a much better way of passing Christmas day than the usual one, of every seaman getting as drunk as he possibly can. —
1834, Chonos. Arch: & Tres Montes:
Our Christmas day was not such a merry one as we had last year at Port Desire. — Between 30 & 40 miles of coast was surveyed & in the afternoon we found an excellent harbor. — Directly after anchoring we saw a man waving a shirt. A boat was sent & brought two men off. — They turned out to be N. American seamen, who from bad treatment had run away from their vessel when 70 miles from the land.
1835, New Zealand:
Christmas day. — In a few more days the fourth year of our absence from England will be completed. Our first Christmas day was spent at Plymouth; the second at St Martins Cove near Cape Horn; the third at Port Desire in Patagonia; the fourth at anchor in the peninsula of Cape Tres Montes; this fifth here, & the next I trust in Providence again in England. —
We attended Divine Service at P in the Chapel of Pahia; part of the Service was read in English & part in the New Zealand language.
For Christmas of 1836, Darwin had already returned to England. I’ll note that of all these recordings about Christmas while on the voyage, only the last one (“the fourth year of our abscence”) was included in the published Journal and remarks. 1832-1836, later retitled Journal of researches into the natural history and geology of the countries visited during the voyage of H.M.S. Beagle round the world, or, as it is generally known day, The Voyage of the Beagle. Perhaps references to the men aboard the Beagle getting drunk were kept out on purpose. In fact, any reference to drunkedness concerned the people, indigenous or otherwise, of areas Darwin traveled to. Would it be ungentleman-like of Darwin to share with his readers that British men got drunk and stupid?
That said (or asked), check out this phylogenetic Christmas tree Darwin sketched the year following his return to England:
Actually, credit goes to Allison Banks (Update 12/21/12: this no longer appears on her website).