In the days of sail, it was very hard! When steam came along, it could be uncomfortable and very hard work, especially stoking, but it depended on your age. When you are young, a bit of hardship and discomofts doesn't count for much when measured against an interesting life at sea. These days (in my very late 60s), when I see young men working in supermarkets or shops, or a host of other such jobs I feel supremely grateful that when I was at that age, I was out on the high seas living a life of hard work and boredom,with varying amounts of danger and adventure spliced into it from time to time, sailing the whole world all around and venturing as far north as Alaska and as far south as South Georgia almost down by the latitude of Cape Horn.
Can't do it these days. of course, no merchant Navy to speak of and the Royal Navy reduced to a shadow of what it was only a few years ago!
Bob