I dont think my drains would work above the WL, If they did they would be slow I think, thats why I decided to plumb them to the head, it will supply the head with water and if I need more drainage I can just pump the head clear. Just one sink and the toilet draining into the holding take I am hoping it will be fine, since the marinia I will be docked at has free pump out for members I will be monitoring it close this year to see how often it fills.

It would depend on your boat, ours has enough freeboard that the sink thru hulls work fine above the WL. Your's may not.
You can find ideas for composted toilets if you google. Ours is a 5 Gal bucket with an oil funnel, as a pee collector, bolted on the inside. It channels the pee to a 1 gal bottle. A regular toilet seat tops it off. Use coconut peat and there's no smell. The wife thinks its the only way to go.

cheers

Yeah it helps. Thanks! No diesel. Small outboard. I have 3 below WL thru hulls, I think I am doing away with all of them, one for the vanity sink, thinking about doing away with that sink anyhow to open up more storage, one for the galley sink which I am currently removing, the sea cock for that one was under the cabinets hard to reach, its a stupid place, and then I have one for the toilet. I dont think the wife will be open for a composting toilet so my plan is to plumb the galley sink to the toilet and then do away with the thru hull. I figure if it doesnt work, I can easily put that one back in next season in a bit different location. The bilge pump is above the waterline on the back so I feel OK with that one. How did you make your own composter? Are the plans online? I am interested in that but it will take some time to convince the wife thats the way to go.

hi rainhh202
I have no under the WL thru holes, able to do that because the head is composting and we don't have a diesel. As far as I'm concerned they are the only systems that usually use submerged thru hulls. If you have a diesel, I don't think there's much you can do about it. The head you can toss out along with the silly black water tank and get a composter, they are worthwhile (I built my own for $30).

Some boats have one to pump sea water into the galley sink, I don't see the need. I do have a few above the WL thru hulls, can't avoid those, they have no valves and drain two sinks and for 2 bilge pumps. The bilge pump thru hulls needed one way valves added as water was coming in when sailing hard, boat was heeling and they were getting submerged.

Anyway, I love a dead dry bilge.

hope this helps

Hey Capt...I am new to sailing and working on getting my boat up to speed...the PO said it was sailworthy but there are somethings that bug me, one of them being the thru hulls, they are the original gate valves. I was cruising through the posts and noticed in one that you said you had no thru hulls? Do you find this annoying? I was thinking about removing mine completely because frankly they sort of scare me, a big hole in the bottom...yeah I know properly maintained they work but still...a more simple no hole boat makes more sense, less maintenance in the long run. Anyhow I was wondering if it really is a big deal not to have them?