Ah, an early application of the three watch system.
The White Star Line may have been innovative but it did not help their ship, R.M.S. Titanic.
Interestingly the article says, "With a yell, the officer shouts to the helmsman "port" or it may be "starboard"......Another second and the great ship is either safe or sinking beneath the waves". How prophetic. This article from 2008 almost describes what happened four years later on the night of 14th April 1912 when at 23:40 (ship's time) the great liner struck an iceberg.
But this is off topic.
Getting back to the question raised by "fuzzflyer", with a crew of eight, I would have three watches, two persons per watch. The other two would be "daymen" looking after the tasks to be done during "normal" hours such as cooking, cleaning etc. and being available to be called out if heavier work is to be done at night. The six watchkeepers I would have doing four on - eight off. Pretty bog standard watchkeeping routine but it works.
When heavy weather or intense cold is encountered I would have the two "daymen" chip in and take a dog watch between 03:00 and 05:00 to make he night and morning watches a little shorter.
Aye // Stephen