by jib alone?

[navahoIII]

Went for a sail yesterday at the lake where I keep the boat. There was a steady, what I would guess was a, 'gentle breeze' with stronger gusts. I ended up not going out and taking a swim instead.

I wasn't sure what to do. Normally, I use the mainsail only when single-handing as the jib sheets are too far forward to make for a comfortable time of it. There are no reef points on the main and it has the infamous 'roller reefing' built into the boom. I didn't want to go out with a full main and had never used the roller reefing feature. And, trying to employ it before heading out seemed a tall task, where the main would have to be hoisted all the way before lowering it enough to roll what you need onto the boom, against a wind trying to prevent it. Then, if you succeed, the mid-boom sheeting has to be reattached to the end of the boom. I imagine that would still make it possible to control the main from that location although doesn't that mean the main sheet runs from the jammer on the centerboard trunk to the boom's end in a diagonal line from low to high? And is that in the way of the helmsman as he moves around?

Then I wondered if the jib alone could be used (don't have roller furling) and where should the centerboard be positioned in that case (?). When using the main alone I pull the centerboard handle (DS1 - 1961) about half way back and she seems well balanced and sails fine.

Thoughts, advice?

navahoIII
'Annie'

[GreenLake]

I'm going to be a bit general in my reply. Your basic issue, as I understand it, is that you were faced with wind conditions you were not comfortable sailing in. I would first like to understand a bit more precisely where your limits are, then discuss what can be done generally to expand those limits and finally address the implications of sailing with only one of the sails.

Can you translate your wind estimates into numerical speeds? For example, if you could observe occasional white caps, your gusts would be around 15 knots or higher. The earliest tentative white caps form, I believe, from 11 knots upwards, but there's a difference between sustained winds acting over a longer fetch, and more localized gusts.

Another useful indicator: any flags on land will start to blow straight from around 12 knots.

I think of about 6 knots and up when I hear "gentle breeze". Around 6 knots, the air will no longer flow laminar over the water, but the whole column is turbulent. That means that the bottom parts of your sails get the same wind as the upper part (see here) and that contributes to the sense that your boat shifts from drifting to really sailing. From about that wind speed, sailing becomes enjoyable By 8-10 knots of true wind, you boat starts to definitely move and heel. Unless you go much above 10, the experience should be mostly fun and not challenging (unless the wind fluctuates very erratically).

I have a personal benchmark of about 14 knots for gusts. Up to around that point, I can comfortably manage them single-handed. Especially if they are isolated. (A reef will extend that range a bit - if this seems conservative to some, I don't like to hike aggressively when I sail by myself, and it's not something which we get a lot of chance to practice.)

An aside: a friend gave me one of those cute little hand-held anemometers. I used that for a while, until I learned to map its reading to the sea state. Now the latter has become second nature. Just like I used a GPS to get an idea of boat speed, but by now, I'm fairly accurate reading that from the shape of the wake.

Before I go put in a reef, there are three key things that I rely on to handle gusts.

1. I use ratchet blocks for main and jib sheet. I can hold both in the same hand and don't need to cleat. I don't need to sit in line with the jib cleats, and I can't be caught with a cleated sheet not releasing promptly.
2. I use a vang to keep the boom from rising when the main is released. That prevents the main from powering up when I open the main in a gust. You'd be surprised what difference that makes.
3. I tie the jib sheets together, so they form a continuous loop. That way, if I can reach any piece of jib sheet, I can always pull at it to get the part that I need to operate. To make this work, one needs to either have cleats at the fairlead, or non-captive cleats at the CB. (I have the latter).

Sailing with main alone: I think you got that description right. Moving the CB aft, by swinging it part way helps balance the boat, because the lack of the jib means that your center of effort is now further back. (See also here).

Sailing with jib alone: you would need to move your CB forward, but there's no way to do that. If you see bigger boats sail with jib alone, I believe there are two factors that may be in play. The first is that some of them have genoas with significant overlap. Part of their sail surface is behind the mast. Many of these boats tend to have a smaller main. That means dropping that (or not hoisting it) may result in a less significant impact on boat balance. Second, this is often done when reaching or running.

In addition to these, keel boats are sailed heeled where we tend to sail the DS flat. That means, the hull shape my also counteract the lack of a main in a way that's not accessible when sailing a DS.