Marine toliet system – Sealand VacuFlush 5000 toilet, J Series Vacuum Generator and 125 litre Wrengco sullage tank

The issue of sullage is an emotive issue on any boat and until recently it was no different on Lucey Blue. When we bough the boat both the toilets were relatively old and the sullage system undersized and poorly designed.

Nick replaced the port toilet and plumbing with a standard manual Jabsco toilet – simple, effective and reliable. The starboard system took longer to design and quite a while to install. Removing the old toilet systems was not a pleasant experience for Nick, however, it reminded him why it is important to do a job right the first time and probably resulted in the new toilet systems being overbuilt!!!!

After a bit of consideration, redesigning and recalculating we decided to install a new Sealand VacuFlush 5000 toilet, J series vacuum generator and 125 litre holding tank in the starboard hull. The old system consisted of an electric Jabsco macerating toilet and a 40 litre Vetus sullage tank (located under the double bunk in our aft cabin). The tank filled in no time, the pipes were always full of waste and the system smelt……yuk….

Ryan chipped in as always and provided some great instructions – incredibly realistic for a 4 year old. However, we also sought advice from Charles Parsons (Marine Advisory Services, Annandale NSW). If you ever need advice on marine toilet systems we cannot recommend Charles highly enough.

The new design has the Wrengco sullage tank and Dometic vacuum generator located in the bow locker with a single PVC pipe connecting the system to the VacuFlush toilet. No more standing waste, no more sullage near “inhabited” areas of the boat and simple access for maintenance etc.


After removing the old system, the first step was to install a shelf in the bow locker for the sullage tank. Nick had forgotten how much fun it can be grinding fibreglass and using resin in a confined space. With the help of a long snorkel (made from new [unused] toilet hose) he made it out of the locker alive after a few hours!!!




The next step was to install the PVC sullage pipe – carefully ensuring a consistent downhill slope from the toilet to the vacuum generator in the bow locker. The PVC air vent piping runs uphill from the holding tank through the bow locker bulkhead, then under the headliner in the forward cabin to the anchor locker where it connects to a carbon filter before it finally vents to a point under the bridge deck (or when at sea to a point in the anchor locker itself).

With the shelf in and plumping in place it was time to install the Dometic Tank Watch 4 monitoring system into the sullage tank before connecting the vacuum generator and tank to the rest of the system. The Dometic Tank Watch 4 is great – no more guessing (and crossing your legs) if the tank if empty or nearly full!!!






The sullage tank is mounted high in the bow locker and has 1 ½ inch drain at the bottom that is split into two 1 ½ inch Vetus impermeable sanitary hoses– one to the through hull fitting and the other to the deck-mounted pump out fitting. Very simple and very, very quick to empty – no pumping just gravity drain or suction from the pump out station vacuum.


While the job sounds simple enough the boat looked like a bomb-site for several weekends with bits of plumbing, electrical wiring and bolts everywhere….



Emily and Ryan helped out passing tools, finding parts and pulling wires through hard to reach corners of the boat. By the end of most days they were tired and ready for a treat or two!!!!




Before too long – but what felt like an eternity to Nick – the “tank” end of the new toilet system was complete and it was time to get onto the toilet itself. This final stage was relatively easy – unwrap all the components, install the base funnel, bolt the toilet to the base and attached the water supply. The hardest part was tightening the bolts “in reverse” while working upside down in hard to reach corners using a mirror – by 22:30 in the evening Nick found it hard to crack a smile.




We are really happy with the new VacuFlush toilet and tank setup. The VacuFlush uses very little water and thus the holding tank lasts much, much longer than normal. Dometic claims a VacuFlush system connected to a 100 litre sullage tank provides the same number of flushes as a 400 litre tank connected to a typical electric macerating toilet.

Overall we think we made the right choice – the system is very easy to use, simple to maintain, quiet, efficient in terms of power and waste storage and best of all it does not smell!!!!!!

Lagoon 42 TPI Owner's Manual

Shortly after we purchased Lucey Blue in December 2009, we went in search of the holy grail....a copy of the Lagoon 42 TPI Owner's Manual!

After Google-ing, Yahoo-ing and even contacting Lagoon in France and TPI in Rhode Island, Nick resorted to pleas on various forums such as Multihulls4us, Cruisers Forum and the Lagoon Catamaran Owners Group on Yahoo.

Graham, on Vinga III (in the Caribbean) answered one of these pleas and very generously made us a photocopy of his 89 page Owner's Manual and sent it to us in Australia.

Nick spent a couple of fun-filled hours scanning in this document today and we have uploaded it to Google documents, so that the other approximately 50 Lagoon 42 TPI owners (or prospective purchasers) can easily have access to it.


Check it out here:
Lagoon 42 TPI Owner's Manual

A huge thank you goes to Graham. We really appreciate your help, and hope to meet you some day!

PS. Having gone to these lengths to obtain this document, we then met Ian (of Skipper's Daughters - another Lagoon 42 TPI located in the UK) last weekend...who, of course, informed us he also had a copy of this 'scarce as hen's teeth' document. Isn't it always the way?!

Lagoon 42 TPI construction - Replacing through hull fittings

After the sail drives it was time to “move forward” and overhaul the old skin fittings in the starboard bow locker. The story goes that the first owner of Lucey Blue was a Cuban who put the boat into charter for a few years to help pay for his new toy. We don’t know how the owner managed to get around the US embargo against Cuba, but that is another story. The bottom line is that in order to maximise the number of bunks available for customers the owner installed a bed in the port bow locker and a toilet in the starboard locker for the skipper. The bulk of this strange setup has long since been removed leaving a couple of old fittings that were starting to look a bit suspect.


The idea was to replace the ball valves and then later install a large holding tank and salt water deck wash system. Like most jobs it turned out to be a bit more complex than originally planned and before long it was apparent that the through hull skin fittings would also need to be replaced. Removing the fittings was easy enough and it was a simple matter of another trip to the ship chandlery to find replacements. But that pesky owner had cut some corners and the end grain balsa core had not been sealed after the holes had been bored through the hull. The net result of the “Cuban shortcut” was a wet patch of balsa core around one of the skin fittings - approximately 15 cm in diameter - that had to be dried out over a few days before I could seal the exposed areas with epoxy bog. We ended up checking all the skin fittings on Lucey Blue just to be safe – no other problems identified.


Despite the extra time the repair was easy and the hull cross-section confirmed the robust construction of Lucey Blue. All Lagoon 42s were built in Rhode Island by Tillotson Pearson Inc. (TPI) using their state of the art infusion process and vinyl ester resins.


The hull thickness near the bow on Lucey Blue is about 2.5cm - with an outer fiberglass laminate of about 4mm and an inner fiberglass laminate of 5mm. I guess in the old days the cost of resin was a bit cheaper and TPI were keen to ensure a high quality build to support Lagoon’s entry into the US market, but talk about overkill….


We are still considering the best toilet and sullage tank system. But with our shiny new skin fittings it should be a simple plug and play solution.


Another interesting task complete - hopefully we won’t find any more surprises onboard!!!