I'm not navy. We don't use tattletales on mooring lines. When it starts getting skinny and hard as iron, and starts squeaking and burning on the bitts, then you know it's gonna go. But parting mooring lines is actually pretty rare on merchant ships. I guess we get more practice, and we have fewer people interfering with the process.
I would never carry rocks to sea. Too much weight in the seabag and 50 lbs dont leave you much room for the clothes and gear you might need for any climate in the world for the next 4 months or more. Practically all my jobs are flyouts and its already hard enough to not go overweight on the baggage. Even for a pierhead jump, most likely I will still have to fly home. If I will be honing something, I take some lapping film and find some glass on the ship. For my own shaving razor I got my pasted balsa. Or a shavette and some Feathers. For my knives, a carbide pull-through gitser sharp in about 4 seconds.
You Guys Have an amazing amount of respect from me Slash. Merchant Sailors have always been held in the highest regards by me and my whole Family because although we go into harms way, we are prepared for it and well armed, Merchant Vessels are not and when something bad occurs on the high seas such as Piracy, you are in far higher levels of are and yet you do the job anyways which gives you 100% of my Respect my Friend. You are absolutely correct, 50 lbs is not much at all and with that limitation you are definitely hard pressed to get what you need for clothes on board much less extra weight of stones so great call on the small carbide for knives and film for razors