The Holding TankThe Joys of Marine Toilet Maintenance - The Holding Tank

Article and photos by Chris Ayres


Garry’s Anchorage, Fraser Island. I was crew. In answer to an urgent scream from nature I had just repaired a dreadful manual toilet. Disaster ensued.
“I can’t understand why the holding tank is full, old boy!” Steve, the skipper said. “I’ve never used it! I say, old chap, why don’t you just nip down to the bilge for me and see what the problem is? You seem good at these sort of things.”
Without a word, I grabbed my kit, leapt on deck, dived overboard, narrowly missing the open jaws of a tiger shark, avoiding the startled crocs that were circling the boat, stepping across one 20 metre monster I used as a bridge to escape the thrashing tails of the manta rays and somehow managed not to be stung by the circling clusters of box jelly fish.
As I stepped ashore, I took care to avoid the spikes of the stone-fish, before running up the beach ducking a taipan in a tree, past a pack of dingoes howling for blood and brushed aside the national park rangers demanding money with menaces … not stopping until I reached home.
That was five years ago.

The Problem

Since then, a humane and caring government has enacted legislation making manual marine toilets non-compliant (ie illegal) and thus liberating pressed-ganged crew from the odious task of repairing these devices of Satan.
As part of their duty as signatories to the International Convention for the Prevention of Pollution from Ships, Federal and thence State (and Territory) governments enacted wondrous new laws banning the discharge of nasty things described as ‘thermotolerant coliforms’ containing ‘suspended solids’ – sewage to you and me – from our vessels unless such things had been treated in a way that “the relevant level of the total suspended solids content of the samples of treated sewage taken during the test period must not be more than 50mg/l above the suspended solids content of ambient water used for flushing purposes.”
Got that?
And at one stroke created a new problem.

Research into Solids

Being – as are we all – a law abiding lover of all things regulatory especially those that carry a penalty in Penalty Units exceeding my net worth by a factor of 17 – I determined to find a way to comply with these new laws and solve the riddle they created.
Politicians, being by their very natures frivolous creatures with short attention spans, having passed these laws in every state of the Commonwealth, promptly forgot about them. Leaving the products whose discharge they were prohibiting for us to solve.
Meanwhile NIMBY local governments added equations to the riddle, by screaming “no pump-out stations in my backyard” or words to that legislative effect. Apparently our salty substances, macerated to 50 mg/l or not, were not welcome, and tended to contaminate (not sure how you contaminate effluent, but never mind) the pristine sewerage systems of the posh waterfront councils.
Thus we have approximately 18 pump-out stations in the entire East Coast of Australia of which nine are actually working. At a cruising range of 50 miles a day and not stopping, a normal couple on a yacht circumnavigating the 22,292km coast of Australia, would need a holding tank of 2,972 litres. Bit tight on a 36ft yacht, I thought.
My research on Big Tanks took me to the tragic loss of the American destroyer, the USS Bogger. She was blasted clear out of the water. The cause? An ordinary seaman Randy Rogers, who upon been chastised by a very petty Petty Officer into not smoking on board, had attempted to extinguish his Camel cigarette down the heads. Apparently methane created by coliforms can become very thermo-intolerant of smokers.
Crocodiles have been reported on Fraser Island.On the boat from which I had escaped, the holding tank had set solid, never to be discharged again. This is not unusual, I found. I have heard of yachts brought in from overseas where the holding tanks are chock full. (Now there’s a novel way to dispose of unwanted suspended solids where one has not room for a 3,000 litre holding tank – export it!)
But there is a loophole. In the law … not the holding tank, now. Keep up. It is permissible to discharge your holding tank (if the coliforms have not solidified) without benefit of one of the nine pump-out stations if you are:
    1.    More than three miles offshore in Queensland (one mile NSW and not at all in Victoria I believe – a constipated state of affairs it seems);
    2.    One mile in certain parts of Queensland (for the time being);
Just step in here, Dear!    3.    In various Designated Areas, such as well away from marinas, creeks, those ghastly canal estates, swimming places, recreation areas etc; and
    4.    In some parts of the great Barrier Reef (See the Schedules of the Regulations to the Act). But the law – like the universe – is in a constant state of change so watch out. Originally, the government was to supply coloured maps of discharge areas but some wit must have pointed out that choosing the appropriate colours might give rise to confusion.


I have seen one yacht convert his entire saloon into a treatment works and holding tank. It complies with the law, but not the crew. He has become a single-hander of necessity. Another yacht I know has sacrificed marital bliss by converting the underside of a double bunk to a holding tank. Yet another yacht uses a separate electric pump to ‘empty’ the holding tank. Alas, no pump known to marine science can ever fully empty anything, least of all the dregs of a holding tank.
So I had to think outside the square.
My holding tank could not be more than 64 litres (nothing else would fit in the space available), it had to be able to be emptied by gravity and thereby avoid the cementation process of the little coliforms. It had also to be properly vented. The tank also had to have the pump-out – should I ever find station and one which actually works – directly above the inlet/outlet. Apparently, some pump-out pumps are so powerful, they cause the tank to implode – much like the ill-fated USS Blogger, but less spectacular.
To operate my design, the outlet seacock is closed (naturally), the inlet open. The macerator macerates to lawful size, and deposits same into the tank.
Once at the lawful spot, should the tank require discharge, it can be done as I sail my three miles, one mile or whatever, offshore, ensuring first I am nowhere within the legal confines of a Designated Area, Reef, Marine Park, Creek, Estuary, Enclosed Waterway, Canal Estate, Beach or Recreational Waterway etc, etc. The venturi effect of the vessel on a good beam run ensures a trouble free and legal discharge of all unwanted coliforms. No need to sell the boat, to export it, or find slave labour to excavate a buried solidified tank. No nasty musty residual aromas, not now I know 65 won’t go into 64. In short, it works.


I am on my knees. In the heads. Thrusting a long white Anaconda with a heated end through a small hole into a locker. Inside the locker the sweet and gentle voice of my beloved screams, “Push! Push! Harder! That’s good! Ouch the #@$%ing thing’s hot!”
An elderly neighbour from an adjacent yacht approaches curiously: “Gladys! Quick! Come and look at this! The best equipped boat in the marina! Chris carries a spare woman in his locker!”
Said ‘spare woman’ mutters something no-one hears – fortunately. Please let me explain how aforementioned ‘spare woman’ ended up in the locker. Now don’t leap to the wrong conclusion about white slavery.
On Lady Lonsdale (our boat, not my partner through thick and thin – keep up), I had tried the locker myself. I even got in. But not out. I was jammed tight head first. It took Emergency Services three hours to extract me. There was only one other person who could both access and exit the locker WITH the 64 litre holding tank, a fist full of hose clamps, several screwdrivers (to feed to the Bilge Monster), and could be bribed to comply.
She also made a far, far better job of it than any man could ever have done. Heck, what else could a bloke do? You girls out there all know men can’t do two things at once – connect the Cobra to the tank AND strangle it with a hose clamp!

The End of it all

So where I began with The Macerator, progressed to the horrors of the Bean Counter Baby manual loo, it all leads to the same place – the holding tank. And there it should remain.