Over the last few weeks we have been trying to source the cause of a pressure loss on the water maker from the test/live valve on the boat.

This is an external port in the deck that allows us to test and confirm the quality of the water we’re producing through a test pipe before we switch the valve across and run the water into water bags for storage. It also means we can test the water quality in bad water without having to open any hatches, and risk taking water below decks which can can cause damage or contamination.

Our Spectra Watermaker produces an impressive 24 litres of fresh, drinkable water each hour, or it should.  On Saturday we ran a capacity test where we ran the watermaker for a minute and multiplied the production by 60, and again we came up some way short. Our latest attempt to fix the problem hadn’t worked.

We experienced the same issue on the Great Barrier trip.  We'd still make it across the Tasman as it was, but it's not ideal as it means we have to run the watermaker longer to achieve the same water production, which in turn requires more power.

We could see the source of the pressure loss still - water was dribbling down the cockpit well from the test valve - but we couldn't discover why. Today, one of our final days in New Zealand, we called in the big guns from Enertec Marine who came down to investigate the issue.

It didn’t take long for a pair of expert eyes to solve the issue.

The cause was so small, the actual fitting - a simple 'o' ring was less than half the size of my smallest finger nail. The second part of the cause was the watermaker pipe was just a few mm short of reaching its required port in the valve. A finger nail size problem was responsible for a 30 per cent loss in capacity.

We replaced the 'o' ring, extended the pipe, sealed the unit, turned the watermaker on and - Robert's your father's brother - we're back up to full speed.

Now, back to packing up the boat. More about that later on.