Toilets (or Heads) on a boat are generally disgusting. I can't tell you how many boats we've been on that smell…no…reek with the stench of urine or sewerage. Doesn't matter the size, cost, or type (sailboats, mini-mega yachts, center console, charter fishing boats, scuba boats, hydrofoil passenger cats) it seems more than half have a stench in the heads while even a large percentage of that have the stench throughout the entire boat. Below are a few solutions that we've found that work for us.
The Commoderizer (for marine heads)- I tried toilet bowl drops, we tried two different brands of toilet bowl tablets but nothing seems to combat the rotten egg smell that comes from a salt water toilet as well as the Commoderizer. Trust me, I fought liking this thing with every inch of persistence I could muster! It's not cheap but it does a damn fine job. Not only does it remove the odor from the toilet bowl, it cleans the pipes and tank as well. If you know anything about replacing sewer hoses and tanks in a boat, you'll understand the calcium build up issue I'm referring to. The Commoderizer tablets help keep the smell down from the water intake, meaning less smells inside the cabins, heads, walls, a/c vents and everywhere that sewerage or rotten egg smell can permeate (and trust me, it will permeate through any hose or wall). A single tablet is supposed to last 2 weeks but it lasts us about 3. The owner is offering a discount if you use the code WYNNS when you purchase. It's good for anything on the site. Buy it here: http://bit.ly/2jtgyOO
Nature's Head Composting Toilet – We have an entire series about why we love this toilet: gonewiththewynns.com/all-composting-toilet. It has worked flawlessly for years in the RV and so far it's working well in the Sailboat. I'll go ahead and answer the one question we get all the time: It smells way less than a standard marine toilet, in fact there's almost no smell during use. The one caveat I have at the moment: I'm not sure if we'll find coco COIR as we travel (of course we can always order online so it's not a huge deal for us). That said, if you're a coastal cruiser, you live on a mooring ball or at a marina, or if you're on a lake or doing the great loop, this is no doubt the best toilet you can purchase for your boat. Larry (the owner of the company) is offering up a discount that beats the Amazon price. Click this link: Buy From Nature's Head Directlyand the discount will be applied at checkout. If you want any extras the discount is good for the entire website, and you'll get free shipping if he can fit it in the toilet box. It's a good idea to buy a spare fan and for some applications a spare liquid tank too.
Quiet Flush Marine Head – This quiet flush macerating toilet is 100 times better than the manual pump head that's found on most boats. We've had our issues with this toilet but these issues stem from improper use by the previous owner. I am working on a new macerator pump from Raritan that should be an upgrade, but for now this setup is pretty darn good. Especially when paired with the Commoderizer we mentioned above.
If you're wondering why we didn't install 3 composting heads, here is the answer: We wanted to keep one head that can be flushed into the sea while we are out sailing in the open ocean (where it is legal to do so). The last thing we wanted to do was get rid of a perfectly good toilet before getting any blue water sailing under our belts. The idea being we will go through less coco coir and not need to worry about dumping toilets on long crossings. After using it for 6 months we are happy we have the variety of heads that we can use based on the location of where we are sailing. Buy it here: http://amzn.to/2kIZaq6 If we only had one head on board, it would hands down be a composting toilet.
Fresh Water Flush – Some people prefer to go the fresh water flush route, which works, but uses a lot of fresh water. If you're not overflowing with more freshwater than you can use I don't think this is a solid option. To really flush out the pipes you need to use a couple gallons of water per flush, and with two people on board that adds up to 20+ gallons per day.