A Kiwi couple's cruising adventures on America's Great Loop and around the coast of New Zealand

Wednesday, 26 February 2014

Next instalment (#4)

The day after we arrived at Opua marina, so did the wind. The girls took off for their favourite pastime (shopping) and Charlie and I set to making up a permanent bridle, which was the same as the last temporary one but had thick plastic hose over it to prevent chaffing, the loops on the end were spliced, not tied, and the hook for the anchor chain was secured with a shackle, rather than a knot. By the time we were done, the wind was gusting 40 knots and waves were continually breaking over the breakwater, however it eased off in the evening and became quite pleasant overnight.

The girls stayed in Kerikeri that night and brought the provisions back the next day to be loaded so we could depart back out into the bay. By then the wind had dropped considerably and we had a good trip back the 10NM to Omakiwi Cove (of course). We had arranged for Aunty Lyn to come up and stay with us for a weekend so we were going to pick her up from Dove's Bay marina on the other side of the Bay, and refuel at the same time. This was going to be a critical refuelling as it was the first since we left Auckland an would show us how much fuel both the boat and the genset were using. We had found that we needed to run the genset about 5 hours a day to keep the batteries charged and the refrigeration down. This usually comprised an hour in the morning while we cooked breakfast, and hour around midday (lunch) and 3 hours in the evening (dinner). Just as an aside, I found the icemaker is a good beer fridge and only has to be switched on with the morning one hour genset run to keep the drinks cold all day! From the genset specs, I had figured we should be using around 1 - 1.5 litres an hour, but we had never confirmed this. As I had been running the genset off just one tank since our last refill, its consumption would be the difference between the two fuel tanks when we refuelled. However, I became concerned that the fuel gauge on the starboard tank was reading rather low and was mindful that the genset had done 67 hours since our last fuel up. Since I didn't want to run out of fuel on one engine I decided to switch the genset to the Port tank, but not before I had figured a way of calculating the genset consumption with fuel being drawn off both tanks. Amazingly I fell back on my schoolboy algebra, and came up with a series of algorithms that gave the necessary information ( a real mathematician would probably have got it down to a single equation - but I ain't that clever!). I used a couple of examples to test it and it came out spot on each time. Then, and only then, did I change the genset over to the other tank. I even put the formulas down on an excel spreadsheet, so I only had to put in the data and it works out the results for me.

Off we went to Dove's Bay marina the day before Lyn's pickup and refuelled. We took on 512 litres in one tank and 435 litres in the other, so from the engine and genset hours I could calculate that the genset had been using 1.25 litres per hour, and the boat 22.8 litres and hour (both engines). While I was not surprised at the genset data, as it was about what I expected, it was good to have it confirmed. It means it costs about $2 an hour to run the genset, which also confirms the suspicion I was getting that it would be uneconomical to make too many changes to the boat to make it more "self reliant" (such as replacing the electric cooking with gas, more house batteries, PV solar panels etc). For every $1000 spent on "upgrades", I can get 500 hours on the genset, so it becomes a bit of a no-brainer. The engine consumptions were as delightful as they were unexpected. During our Great Loop experience, we changed our pattern of boat speed as we went along and, although I knew that we used one third of the fuel at the end that we did at the beginning (9 knots vs 15 knots will do that!), I hadn't actually collected the correct data to accurately work out the consumption. Our last boat, Kindred Spirit, consumed 35 litres an hour at 14 knots, which equates to 0.4NM per litre. On this trip Loopy Kiwi consumed 22.8 l/hr at 9 knots which equals 0.4NM per litre. OK, Kindred Spirit travelled half as fast again as we do now, but we're quite happy at 9 knots, particularly knowing what happens to the fuel burn when we push Loopy Kiwi up to 15 or more. Of course this data will be updated when we next fill with fuel, but to date it looks like those figures will remain fairly accurate.

We spent the night in Crowles Bay, just around the corner from the marina, and in the morning went back to pick Lyn up. Then, where else of course, but across to OKC! (you can see from the pix below why it is so appealing.

By this time on our holiday, it was the end of January so most of the boats that had journeyed up from Auckland had gone home, and during the week you tended to have comparatively few boats in the Bay. However, over the weekend the locals come out to play and OKC was fairly busy each night, with a fair amount of partying going on as well. OKC has a steep, sandy beach and big tides reach right to the shoreline. We would go ashore each day and the girls would go for a swim. Woody would stand on the shore a while, fretting over some of his "pack" being in danger, until he could stand it no longer. He would first wade, then swim out to the girls, rounding them up like a flock of sheep until they followed him back to shore.
On Sunday, we decided to cross the Bay to drop Lyn off on Monday, and do a bit of fishing on the way at a well known fishing spot called "middle foul". Unfortunately, the brisk NE wind and 2 metre swell decided against our doing so, so we tucked in up the Mangonui Inlet and had a go there. While not the best fishing spot, we did manage to catch enough for a feed, and then anchored up in Patunui Bay for the night. Here's the map again to remind you where all these places are:
We dropped Lyn off at Doves Bay marina, and met up with Charlie and Pauline again, who intended to join us for the next portion of our journey, North to Whangaroa Harbour. This entailed the girls (including Lyn) going shopping for the day in Kerikeri, then Lyn departing while the other 2 drove to Whangaroa. In the mean time, Charlie and I got to take the boat to sea again and battle our way up the coast to the harbour. But we will talk about that next time.

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