It was still early, around 7am, when I started Liffey's engine and pulled up the anchor at Elephant Cove on Happy Jack Island preparing to head back to Liffey's mooring on the Tamaki River. Diane and I had been cruising the Western Coromandel for seven days in the company of varying numbers of other H28 Association members and their boats.
It was realized as we put Liffey in gear to motor out of the bay that we had no drive power. The drive shaft was certainly turning. Had the prop fallen off perhaps?
I quickly formulated a plan to sail as far as we could and if necessary call Coastguard for a tow. Umm!
We unfurled the headsail and drifted out of the bay. Yes, there was pretty much no wind this day and "Plan A" wasn't looking too good! By this time crew on several of the other boats had realized that something was not right and Nick Hoyles and his wife Claire (Stamp Machine) chased after us in their inflatable. Nick was able to convince me to go back in to the bay so we could see what might be done to fix the problem.
So with me on board steering and Nick and Rory in their inflatables holding on to each side of Liffey we were towed the short distance back to the relative protection of the bay. We dropped anchor in 6m (20') of water to discuss how we might proceed.

Nick climbed on board and Claire motored back to her own boat. I agreed to get in the water and try to get a better idea of what we were facing. So on with the mask, snorkel and fins and over the side I went.
I was pleased to see that we still had a prop. I tried turning it and found that it spun freely on the shaft. Well that was clearly a problem.
Having reported this finding to Nick he was able to go in to much detail about how props are attached to shafts and convinced me that we would be able to fix it.
So I was back under Liffey with visegrips securely tied to my wrist and after a couple of attempts, that is a couple of breaths, I was able to remove the split pin and undo the nut holding the prop on. The nut was just finger tight as Nick had earlier speculated it would be.
By this time we had quite a gathering of H28 members and the "Team" as it came to be were offering helpful suggestions. With the likelihood of the prop being dropped when it was taken off the shaft it obviously needed securing. One such helpful suggestion was to use a slipknot it being difficult to tie knots while holding ones breath underwater.
A slipknot it should be pointed out could be tied above water and then it would then be a simple task to slip it over a prop blade and tighten it. Steve (Caranda) suggested a running bowline. This not being a knot I had learned to tie I passed the three metre cord prepared earlier to Steve.

Back under the boat I tightened the knot and, demonstrating implicit faith in Steve's knot tying abilities, slipped the prop off the shaft and allowed it to be hauled up to Liffey for inspection.
About now I was a little surprised to realize that I was starting to enjoy myself. The team was helping with what on my own would have been a stressful situation. It was looking more and more likely that we would be able to get things sorted and, after all, it was another beautiful day on the water.
It was decided that with less than 30 minutes to dead low tide and given the benign conditions that it made sense to continue the exercise in
shallow water where there was no swell and if anything was dropped there would be a reasonable chance of retrieving it.
With an inflatable dinghy either side again, and a scout going ahead on the outlook for rocks and a suitable spot to operate from, Liffey was towed toward the back of the bay. A slightly scary moment for me came when I looked at the GPS and saw that we were being towed at over 4 knots. With the beach looming up I called out to slow down a bit. I need not have been concerned, as these guys knew what they were doing.
The bottom close to the beach was composed of rocks about the size of a fist and larger, worn smooth from being tumbled around, and with patches of white sand several metres wide in places. Larger rocks just under the surface and covered in oyster shells were close by would need to be avoided. The water was crystal clear and at around 22oC was warm enough to be able to operate in safely for hours if necessary even without a wetsuit.
Liffey was pulled up in 1.4m (4'6") of water close to the beach. A line was taken from Liffey to a large boulder on shore. It was a line that Rory had offered and he got quite a ribbing from those around regards a huge birds nest (tangle) that ensued as it was uncoiled. Never mind. It was sorted eventually.
Another line was tied from the stern of Liffey to one of the other H28's moored further out in the bay.
My being able to stand up in the shallow water in between excursions under the boat made my job easier than it had been in the deeper water. Closer examination of the keyway on the prop shaft showed that while the key was still present in the prop shaft it was worn flush with it. A new key needed to be found and the damaged key removed!
A prop is attached firmly to the prop shaft and turns with the shaft. It is prevented from spinning independent of the shaft by virtue of the shaft being tapered so that the prop jams as it is pushed on. To further lock the prop on there is a keyway (slot) on the shaft and the key when fitted to the keyway protrudes slightly and lines up with a keyway on the prop. In the case of Liffey with the key being worn flush there was little to prevent the prop from loosening.

There was some laughter I understand when Ritchie from Monty Python produced a key and holding it up over the side of his dinghy had it slip though his fingers and disappear in 6m of water. Another key was however quickly produced from Caranda and the job continued.
A few taps with a small hammer on a screwdriver underwater dislodged the damaged key and a few scraps of the now empty keyway on the shaft with said screwdriver cleaned it up sufficiently to be able to insert the replacement key which had been coated with a sticky grease. Once inserted in the keyway the key got a couple of taps with the hammer to better seat it and help ensure that it was not going to fall out before the prop was put back on.
The slot in the prop was lined up with the key on the shaft and the nut tightened with an adjustable spanner from Tropic Bird. (While there  was a large crescent on Liffey it proved to be a millimeter too small go around the nut.) A split pin was inserted then bent over and the job was done.
Back on Liffey now the lines were caste off and Liffey was turned around. I stood triumphantly on the foredeck with both arms raised in a thumps up gesture to the occupants of some three or four inflatables as they headed off to continue their days adventures or perhaps just to have breakfast.
Just 80 minutes had passed since we were first turned around and towed back in to the bay. A big thank you to the H28 Association and to the crews of those boats in the bay that morning. You guys turned a misfortune in to a triumph:
Monty Python
Stamp Machine
Wright Flyer
and Others
A special thank you to Nick Hoyles (our Chairman) on Stamp Machine for his intervention and expertise.