Here’s a typical day on a ship underway:
4 hour watch at night. one hour on the bow as lookout, one hour on the bridge as bridge wing lookout, one hour doing autopilot watch, or actually steering the vessel under the total direction and control of the watch officer, one hour doing other seaman duties as directed. 4 hours during the day, one hour on wheel/auto pilot, one hour on lookout, two hours on deck duties. and 4 hours mandatory overtime, doing the rest of the required deck work.
in port, 4 hours doing deck duties, cargo, line work, etc, 8 hours off, 4 more hours doing deck work, then 4 more mandatory deck work OT.
Deck work can consist of cleaning inside or outside the boat (the marine name is soogying), completely cleaning the heads (bathroom showers, toilets, and deck), painting, chipping rust, splicing line, wire, gangway watch, security lookout, and most anything else that needs to be done.
An engineers day is the same hours, with mechanical maintenance, repairs, of all the mechanical and working parts of the ship. This includes the engines, the generators, the fuel systems, the electrical systems, house keeping systems (sewage, potable and wash water systems, sanitary drains), and anything that makes the boat go!
Hers a typical day on a tug:
6 hours on watch, doing line work, (un)/tying up to docks, making tow, breaking tow, keeping the boat clean, doing sanitary, cooking, splicing lines, making coffee, going out and landing and tying up the barge (or untying and sailing), being the lookout in the wheelhouse, or the bow (as needed) relieving the captain or mate for a minute or two while they use the facilities (that you keep clean too) ((of course this is assuming you have the requisite knowkledge to be left alone for a minute while underway)) or you call the other guy to relieve him, going grub shopping, hauling trash off the boat, loading water, or stores while at the dock. (what else have i overlooked?)
Then you have 6 hours off, then you get do repeat the previous paragraph, etc etc etc until it is time to go home.