Dancing with Herself

The Tuamotus Diaries #45, Day 86 – August 22nd 2016

 

Pesto is a great sailing boat. So much in fact that it tends to keep on sailing even when she is at rest. While at anchor or tied to a mooring buoy, as soon as the wind accelerates above the mid-teens, she gets moving. Tacking at angles of approximately 30 degrees to the wind on each side, she will sail as far as the anchor chain or mooring line will allow her, and then turn to the other side and start all over again. When the wind isn’t too strong, the movement is graceful like a dance. When the wind picks up, tough, it can generate a little anxiety.

The text below is an extract of an email I exchanged with a friend, describing a recent experience of intense sailing-at-rest:

 

Pesto is a keen sailor at rest. Originally I thought I had been the driver of such affliction, for all the extra stuff I added to her topsides, notably the solar panels and the bimini cover. Some time ago however, we shared an anchorage with another HR, one with less extra surfaces than Pesto, and it sailed smartly as well, as much as we did, thus reducing my sense of guilt.

If I didn’t make it worse with the addition of extra real estate to the topsides, our current anchoring technique of floating the chain, to which I confess to have become addicted, definitely augments Pesto’s eagerness to sail. With the absence of attrition at the bottom, the chain offers little lateral resistance, and Pesto feels free to sail. It has been bothersome, but our anchor is so strong and oversized that I can live with it.

Another day, however, the problem peaked as we were riding a couple days of some reinforced tradewinds “on steroids” tied to a mooring ball near Fakarava’s S pass. In order to protect the coral, the mooring was built with pure nylon rode – no chain – and to keep the rode away from the surrounding coral, it was also made short. Just before the wind hit I added 40ft of rode of my own to reduce strain on the system. With just the light rode, Pesto was now even more free to sail and, boy she did! She would accelerate between tacks, reaching speeds of 0.7-0.8kts regularly, peaking at 1 knot on a few occasions. Multiply that by Pesto’s 30 tons, and that makes up a lot of kinetic energy, enough to make me nervous about the physical integrity of our mooring. I immediately engaged on a quest to curb the sailing, which would soon prove to be a fastidious one, made worse by the wind-driven chop. It started with our kedge anchor. I first set it ahead, making an angle of ~30degrees with the mooring, keeping the wind in between. But Pesto kept on sailing and at each of its port tacks it kept on pulling the mooring line as before. It then occurred to me to set the anchor at the stern. It was significantly deeper and more corally there, and I feared losing the anchor. So, instead I had to settle by lowering it more or less 100ft amidships from Pesto. Once engaged, the setup did serve to stop Pesto’s movement, and we enjoyed many hours of motion-less tranquility. The tension at the mooring did increase, but I am sure it was still much less than the dynamic loads imposed at each of Pesto’s tacks. The anchor however couldn’t cope with the tension, and was gradually dislodged and we were soon back sailing.

It then downed on me: the coral! Why not use the coral as my kedge anchor? So simple in theory, putting it in practice was a different story. Working alone, with all that chop, on coral 40-45ft deep, and Pesto moving like a wild horse, it took me at least two hours of hard work in the water to finally lash a loop of old rope to a suitable coral – taking care to attach it to the dead portion of the formation. At times, I had to come back halfway through the dive to wait for the curious shark to give me some more working space – some of them were too big and getting to close for comfort.

With the line finally made fast to the coral, I let Pesto complete a long tack to starboard and brought it in. The boat tacked to port and started to gather momentum. As the line ran off its slack, the knot wrapped tight around the cleat and I watched the line moaning as it got stout and thin – confident at first and cautious at last as Pesto kept moving, taking the line to the limit. The forces eventually got in equilibrium, with a substantial improvement in comfort and anxiety, the mooring line once again working under a static load well within its limits. Even the solar panels, now with the boat sitting at a fixed angle to the sun, increased their output substantially. We enjoyed one tranquil afternoon under that setup as well as the first half of the night. The wind started to veer to the South, however, requiring sequential adjustments to the kedged line – with Pesto tacking again in the process. It must have been the increased movement which facilitated the coral’s job, for by the early hours of the next day I was woken up by a bang, only to find the stern line completely slack, and Pesto merrily sailing against the mooring line again. Defeated, I set the anchor alarm with a short radius and a loud warning and went to bed, trying not to notice the cyclical movement as the boat swung from one side to the other.

Pictures taken from the top of our mast on a day of light winds, tied to a mooring line. Here, Pesto is underway on a starboard tack ...
Pictures taken from the top of our mast on a day of light winds, tied to a mooring line. Here, Pesto is about to complete a Port tack. Note the mooring line angled at ~30 degrees.
On this other picture, taken a few moments later, she has already changed direction and is underway on a starboard tack

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