While I'm at it, I'm giving serious thought to a new toilet as well.
I'd give that more than just serious thought...even the best compact manual toilet is worn out after 30 years.
1. How far does the pump push the waste?
That's a variable...but 6' is about as far as bowl contents will move without a lot of help from gravity in the amount of time that anyone will spend pumping a manual toilet. That's why the tank should be no further than about 6' from the toilet.
Does it just leave the bowl or just get past the pump or get part ways down the hoses or will it get all the way to the holding tank (assuming enough pump strokes)?
It will keep moving as long as you keep pumping or until the next user pushes it a little further.
2. Are some manual toilets better than others at pushing it all the way to the tank?
Oh yes! The Raritan
PH II or PHC (compact version) has been rated the best in the industry for about 30 years. The Lavac
is also one of the best.
I'm trying to be mindful of not leaving waste in the hoses.
Rinsing it out before the boat will sit is more important than filling up a tank with flush water.
3a. Can manual toilets really deal with quantities of toilet paper?
Depends on what you mean by "quantities"...most will choke on the half-roll/flush that most landlubber women seem genetically programmed to use. However, if only quick-dissolve TP is used, even an overload will dissolve in an hour or two, so it's not a major problem.
3b. Are some toilets/pumps better than others at quantities of toilet paper?
Better to learn to use less. Half a dozen sheets
is adequate for most situations...but another half dozen isn't gonna clog any decent toilet. It's the huge wad of 50 sheets
at once that marine toilets can't handle...nor can they handle the premium "extra strong, extra soft" TP. The test: tear off a couple of sheets and put 'em in a mason jar or glass of water...come back in an hour. If the water is milky and all you see is "snow" you can flush it on the boat. But if it's still an intact sheet, try another brand. I've seen Charmin and Cottonelle stay intact in a jar of water for a month!
I'd rather not go with an electric macerating toilet if I don't have to (I'm assuming here that they would handle this without difficulty). But an electric toilet is perferable to repeated unclogs at sea .. or even a single unclog.
I wouldn't go with an electric toilet on a 28' sailboat either.
Cost is not the primary issue here; low hassle is the issue.
See my previous reply.