Category Archives: Nemo

“Lee Helm” follow-up

I wanted to post a brief update on the Lee Helm issue in SL boats;Β  I wrote about it last year, but Orca Flotta’s recently posted about it, and one of the boats I first discussed just got a major upgrade (the Nemo II).

This seems a good time to chime-in once more on the issue.

Deviant Helms

Many sailboats in Real Life have unbalanced rigs that make it difficult to sail on a fixed, upwind heading. Some boats will pull into the wind (called a weather helm), and others are rigged to fall away (called a lee helm). These effects are common and not necessarily bad; often a weather helm can be an advantage.

Anyway, eighteen months ago I wrote a short note about this, arguing that certain SL boats behaved as though they had a ‘lee helm’ bias. Go read that post to get the details. πŸ™‚

Mothgirl Dibou kindly commented on the issue. She suggested the SL lee helm effect was a function of the sailing engine’s heel algorithm. As the boat tilted, the bow swung away downwind. I may not have explained that correctly, so go read her comment yourself! πŸ™‚

I’m bringing the issue up here because I initially only found a lee helm in two boats, the TAKO and NEMO. Since then I looked at many more scenarios and it turns out a large percentage of popular SL boats have a lee helm, including Fizz-engine boats, Tako clones, and several Trudeau releases.

Here’s an example sailing Trudeau Twelve. If you set a fixed, upwind course and let go of the helm, over a couple minutes the boat gradually swings leeward. The graphic below shows apparent wind angles, but the real wind angle changes are even greater; the boat physically rotates leeward by several degrees each minute.

This is a small issue, since few skippers will walk away from the helm for several minutes, hoping the boat will sail itself. πŸ™‚

Having said that, let me also comment that several boats in SL don’t show a helm bias. Those “helm neutral” boats include the Wildwind fleet, the boats based on the BBK engine, the Quest fleet line-up, and the recent Trudeau HepCat catamaran.

Although Nemo I had a strong lee helm, the new Nemo II is now on the hem-neutral short-list. πŸ™‚ In my hands, Nemo II sails pretty straight against the wind, and the graphic below makes that point.

If you sail Nemo II close hauled starting from the Hepurn raceline and aim at the NE corner of Mare Sailing Center, you can let go of the tiller. πŸ™‚ The boat will hold a straight line course the whole way. (Note that the boat speed and wind angle are unchanged in the two views below, even though the boat sailed two minutes uncontrolled, and passed over a sim border en route.)

Click (or double click) to enlarge

Anyway, I’ve probably said enough about Lee Helm. It’s a small point for most SL sailors, and I’m pretty sure there is no good-bad to this issue. It’s just a feature of boat design, and as I said earlier, many RL boats also have a helm bias.

There are now many yacht yards and boat builders in SL, and each new vessel that comes down the launch ramp has its own style, character, and ‘goal.’ It’s great that sailors now have so many options to choose from. In that context, lee helm is just a trait that’s built into many boats, and I think it’s far from the most important challenge sailors face on SL’s high seas. πŸ™‚