Learnings from that Low

January 19, 2019

Day 107

Noon Position: 45 49S  97 23E

Course(t)/Speed(kts): ExN 7 – 8

Wind(t/tws): WxS 15 – 21

Sea(t/ft): W10

Sky: Big sun, an open sky. Big squall clouds to the NE

10ths Cloud Cover: 5

Bar(mb): 1006, rising slowly

Cabin Temp(f): 55

Water Temp(f): 44

Relative Humidity(%): 63

Sail: Twins poled out full

Noon-to-Noon Miles Made Good (nm): 153

Miles since departure: 14,916

Avg. Miles/Day: 139

Days since Cape Horn: 50

Miles since Cape Horn: 7,282

Avg. Miles/Day: 146

Longitude Degrees Made Good (degrees minutes): 3 41

Total Longitude Made Good Since Cape Horn (degrees minutes): 164 41

Avg. Long./Day: 3.29

A glorious night of sleep. Wind stayed W hour after hour despite a forecast calling for it to back into the N. Each time I came on deck prepared to haul down the poles, things were unchanged, and I returned to my warm bunk feeling the luckiest man in the world.

Equally glorious, a full day of sun. Not terribly warm sun, but bright and drying in any case. And again, the wind has stayed dead W.

I’ve not done much today beyond lay out wet things and make a to-do list. Mostly I’ve admired my surroundings, the white chinned petrels, the tropical, towering cumulus, the asure blue ocean … though I have mulled over learnings from our most recent big wind event.

Today’s thoughts:

1. More sail is not necessarily better.

The knockdowns we experienced during the first Figure 8 attempt convinced me that I was being too conservative; putting up the storm jib too soon and taking it down too late. From what I could see (most of the fun happend in the dark) Mo was broaching, sliding slant-wise down a sea and rounding up but with so little speed that Monte couldn’t course-correct before the wave struck.  So, I vowed this time to keep sail up and speed up; this would give Monte the needed control. To that end, I’ve not had the storm jib out once this go around.

I think that was the right call; however, it can be overdone.

In the last couple blows, I’ve noticed that as wind increases, Mo still can come off a sea and round up, even when at speed. Recovery is faster with that speed; Monte does have more control, but it’s still many (tense) seconds to get back on course. I reasoned this was *not* due to more sail forward as that would tend to push the bow off the wind, but rather that the hull and rig, themselves, were acting as a sail when presented to the wind as the boat rounded and that they exacerbated the situation. So, I left sail up.

During this blow, that problem became dangerously uncomfortable. So I went against the vow and reduced sail to a dish rag … and Mo’s tendency to round up was reduced. The implication is that too much headsail is, at least in part, driving the tendency to round in high winds.

So, it’s back to square one for me and high wind sail management.

2. The barometer tells the tale.

I had just read in David Burch’s MODERN MARINE WEATHER that “a pressure drop of more than 2mb per 3 hours is a significant drop, implying the probable approach of strong winds, especially when this happens for two consecutive 3-hour periods.” So, when I saw pressure dropping by 4mb in two consecutive two-hour periods (!), this in the early morning when NW winds were still below 30 knots, I knew we were in for it. The bar continued to drop 2mb every two hours for the next eight hours.

3. The final, SW phase of a low can carry a punch.

My experience is that the final, SW phase of a low is usually less windy; that a gale usually goes out softly. Not so, this low. The SW phase saw initial easing of the wind, but then it filled back in and blew over 40 for two more hours.

4. The crazy happens late in a blow and at night.

That the crazy happens late in a blow should not be surprising. By this time winds have been strong for some hours, seas are large and breaking. As wind eases, its downward pressure is released, and seas tend to heap and tumble. But that the finale of a blow always seems to happen in the dark is just flat-out unfair.

5. All learning is provisional, and the provision may remain inscrutable.

This makes two points. One, the decision to gybe Mo in the SW phase of the low so as to keep stern to the the westerly swell was the correct and rational decision. I don’t know why it failed so spectacularly in this low. That said, the evidence it was failing was pretty clear at the time, and I have wet foulies to prove it. Hanging onto the “correct” decision against evidence would have been precarious. Learning: gybing around late in a blow is not always the right move. Why? Dunno.

The larger point, two, is that each low is different; that as important as it is to have at the ready a collection of storm tactics, it is equally important to let them go if/as they fail, even when the failing tactic is sound and has worked before. This can be tough to do. Remember, there is quite a lot of fear rumbling around the pilot house as things are coming undone. Keeping a rational head going is a difficult business.

Ok. Enough philosophy. Back to sun bathing.