Marine heads and holding tanks - a potentially smelly question.

[colingr]

I've only had little boats so the height of sophistication has only run to a chemical porta potti.

Forgive my ignorance but if I buy a proper boat with a proper bog and holding tank am I then forced to search out pump out stations or, for a number one for instance, can it be pumped straight out.

Can the holding tank be pumped out at sea, if so what are the rules?

 

[rhino_mac]

I had a 25" Sportscruiser with a "proper" toilet - bit cramped admittedly.

On mine, it had sea water to fill the bowl (you pumped it in with a handle) then when you flush the toilet it emptied into a holding tank (actually you sucked the water from the bog into the tank by reversing the pump handle). There are electric versions of the same if you don't want to manually pump the water in/out. I think you can get ones that connect to your fresh water tank if you prefer as sea water can be a bit smelly.

To empty it, you had either a pump out fitting on the rear of the boat to suck out the contents of the holding tank (next to the diesel filler - don't get that wrong!) or alternatively, you could open a sea cock in the engine compartment and it had an electric macerator fitted. Flick the switch and it would pump the contents of holding tank into the sea. When finished, flick the macerator off and close the seacock. There were some rules about when you could do this (offshore by x miles I believe).

I think if you pumped it out while on the pontoons you might get some odd looks.

 

[BruceK]

Mine is a constant delight and source of amusement to my young kids. Vacuum operated gulper affair that sounds like a bullfrog during mating season with all sorts of blinking lights to tell you the state of the holding tank. So not so much a flush as a suck with a bit of freshwater for the bowl from fresh water tanks. This goes to a holding tank and mascerator which will evacuate contents while at sea if I don't chuck my guts in the swell what with fannying about with seacocks in the engine room. But tbh, on a plus, zero smell, a bit of a civilised evacuation, but I am waiting for the day the kids throw something in that they shouldn't or a guest of the admiral if you get the drift. Do you even get a mechanic that will fix these things? God forbid it ever packs up, I rather liked the simplicity of the porta potty, because the thought of going elbow deep into the sewers listening out for something that sounds like it might readily take your hand off with a single gulp to fish out a sanitary pad or Beany Baby stuffed toy is enough to make me miserable and shout, just hang your ass over the side dammit.

 

[lisilou]

We have a holding tank on ours. To answer your questions, if you have a holding tank then everything 'dumped' in the loo will pump into there. Your number twos won't go straight out (eeeewww...imagine seeing one of those float past!). When the tank is full, you either go offshore by 2 miles (think that's the official requirement) or find a pump out (again...eeewww).
We empty ours every time we go out, preferably when there's a raggie around (I'm joking...I'm joking!! )
Not an issue for us at all tbh and I'd rather have one than not.
L

 

[prv]

Forgive my ignorance but if I buy a proper boat with a proper bog and holding tank am I then forced to search out pump out stations or, for a number one for instance, can it be pumped straight out.

Can the holding tank be pumped out at sea, if so what are the rules?

The US have very strict rules, parts of Europe have less strict ones, as far as I'm aware there are no rules with legal force in the UK as a whole but there are conventions on what's considerate. Some places also have byelaws. The rest of this post addresses the UK only.

A toilet installation with holding tank will be able to empty over the side. It will usually have a way to go over the side immediately, not using the tank - either there's a diverter valve where you choose "tank" or "sea", or the tank empties by gravity and you can leave the drain valve open so that each flush goes straight through it without stopping.

If you close the drain valve, or set the diverter to "tank", you will hold the waste on board. You would then generally empty it while at sea on the way to your next stop - pumpouts are rarely used on the coast in the UK.

You should hold waste in marinas, anchorages, near swimming beaches, and in general any kind of enclosed water where it isn't going to be flushed away by the tide. Some places, especially in the West Country, have byelaws saying that you must.

Outside those areas, where it won't inconvenience people, you can flush direct to sea. This saves the risk of blocking up the tank, and also the need to empty it - there are places where flushing some wee over the side isn't going to bother anyone, but pulling the plug on a 100-litre tank of shite and paper would be inconsiderate. So little-and-often in direct-to-sea mode makes sense versus occasional big dumps.

Three miles offshore is sometimes quoted as a rule of thumb for where it's appropriate to empty a tank. I would direct-flush wee almost anywhere except enclosed basins or near swimmers.

Pete

 

[colingr]

Thanks for all the answers. Pretty much as I assumed. We were at Hamble Point a couple of weeks ago sat outside the bar when a nearby yacht dumped directly overboard. Not nice and there were some loud comments when the perpetrator came on deck. He didn't seem concerned, however, and wandered of with not so much as a shrug.

 

[l'escargot]

Some boats don't have holding tanks, some have diverter valves so that you can pump out direct to the sea or the holding tank and some just pump into the holding tank where you have the option of pumping out into the sea or through an additional deck pump out to a shore facility.

There are no rules relating to pumping out from leisure boats at sea in the UK but it is considered polite to empty holding tanks as far off shore as possible and marinas usually stipulate that you shouldn't pump out whilst there. If you ensure that everything that is flushed has passed through the digestive system first it soon breaks down and pumps, holding tanks etc. are less likely to suffer blockages.

 

[Robin]

THe USA are especially anal about holding tanks. We have the option via a diverter valve of directly pumping overboard or going to the holding tank. The tank can either be pumped ( gravity dumped in ourcase) overboard more than 3 miles offshore or it can be sucked out. our marina offers a free pumpout, in the berth, weekly by the 'poop boat' and to all comers free on the fuel dock if they buy fuel there. Our diverter valves and seacock have to be locked to prevent accidental misuse, cable ties are accepted as locks. A local boat was fined $400 after an inspection made just inside the 3 mile line, their valves were all in the correct 'tank only' position, but were not locked as they were inbound from the Bahamas and hadn't got round to doing it.AS a double fine avoider we have the locker doors to the seacocks and diverter valves closed and locked with a simple brass combination lock (acceptable provided the valves are plcaed in the correct all to tank position) instead of the cable ties, to save a potentially puke inducing task out at sea In our case we routinely pump everything to the holding tank which ordinarily will get pumped out when back home and if not we can gravity dump it offshore. BUT, I have a little bucket on the aft deck for holding the hang over the side zinc anode in when we are out of our berth, it's tether line allows it to reach the cockpit by the wheel for extra duties if I've downed too many coffees. We had the same arrangement pretty much on the last of our UK owned boats except that the tank had a manual pump instead of gravity dump. We always used the holding tank when in harbours , otherwise the diverter valve was set to pump it and dump it mode and the wee small bucket really was for wee small wees since our main zinc anode was hull mounted not hung over and needing a 'keep the deck clean' garage when pulled up.