“Lee Helm” follow-up

I wanted to post a brief update on the Lee Helm issue in SL boats;  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. 🙂

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! 🙂

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. 🙂

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. 🙂 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. 🙂 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. 🙂

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12 responses to ““Lee Helm” follow-up

  1. Call me lazy but I’m indeed one of the (very few) sailors who sometimes do some RL stuff while the boats’s course is set onto a beacon in far distance.I know there won’t be anything to do for the next few minutes so I sometimes sneak away for visiting the “ceramics department” or at least get some cookies or lit up a ciggie.
    Particularly annoying I find the leehelming in a boat that is made for relaxed cruising and covering great distances, like the T-12 for example.

    And let’s be honest here, in RL you will find 99% of boats have a slight bias for weatherhelm. This makes sense since the boat will eventually turn into the wind and stall when no-one is at the tiller, which comes in handy should you be tossed over board by a wave or something. Lee helm is a bad thing per se and only the most freakish constructions are lee helming.

  2. My Problems more philosophical about the nature of sailing and the limitations of the script engine in SL. RL boats are usually unbalanced but you even that out with the tiller when your steering a compass course or steering towards a landmark, eventually you do that automatically.

    Because the script engine in SL only really allows full rudder deflection your basically Rowing the rudder every few minutes to swing widely around a course, not smooth, not peaceful for cruising and it completely breaks my immersion. I first noticed it with the Fizz2 but its was worse with the fizz3 and the Trudeaus moved from almost no discernible helm effect to being just completely aggravating every time to the point where the only Trudeau boat I’ll sail for pleasure built after the One is the Hepcat (and yes…I am really disappointed by having to say that). My Tahiti Ketch II still is as even natured as ever so its not a server scripting issue…its something new in the boat scripts

    • The magnitude of helm slip is heel dependent, so it probably depends a lot on the wind settings and sailing style. I don’t notice a major issue in T12 or Epicurus, but that could be because I usually sail crewed and with low wind speeds. It’s worth a closer look across many conditions.

  3. Good enough Jane!

    Some boats has “helm” tendences, and I like and assume. It’s a nice point adding to skipper with, as well as LVs, the sea it’s never a skate ring.

    “Even skating inerties play aroun…”

    To all that came from windsurfing, “Vela Llatina Valenciana”, “Llaúd Mallorquí”, “Barca Murciana”, “Bote Canario”, “Patí a Vela” and some other RL Classes, weather or lee helm trim it’s a natural way to sail itself by design.

    In tech words always a trimmed rig baggy or flattened shoud acquire a “helm behaviour” to correct with helm and crew action.

    And I like it always that replicate as soon as possible the RL inspiration.

  4. The last picture is like you showing up with a Polaroid against my
    Canon and Nikons . Shouldn’t poke at the sleeping White Tigers he has big teeth ,Very embed grounded ones at that , <- )

  5. To add my 2 cents 🙂
    Bwind actually has an adjustment within the engine for this, so it is not an effect of heel totally.
    Most of my Quest boats are very close to neutral but not quite.
    They are usually a bit to the lee side, it does take quite a while to be noticeable though.
    The Q-Scow is a weather helm boat because of the single sail and it is kind of strong, at least compare to the rest of my “fleet”.
    Beyond my limited experience on sailing other boats, lee helm could be an effect of heel but only in an extreme wind speed case.

    For Alain, the way the rudders within SL work, they do not have to be on or off like they are now. It could be easily adapted to a “setting” style, meaning 1 click on the arrow key would give the rudder so many degrees to 1 side, and to counter that you would have to hit another key to reset neutral. If you then had a “helming” style boat you could set a counter if needed.

    Q, have a nice day 🙂

    • Thank you for helping explain this issue.
      I agree with you and Orca above; in RL, many boats have a weather helm, and that’s particularly true for those with a single sail. Q-Scow seems to fit that mold! 🙂
      I also like your suggestion of an adjustable rudder setting. So many features common to SL boats are ‘legacy’ from old Tako designs. Adding a graded tiller effect and fixed rudder positions to virtual boats might be a clear, important advance toward a ‘realistic emulation’ of sailing.
      I appreciate that the ‘rudder issue’ isn’t a trivial fix, though. Rudder deflections slow a boat due to drag effects, turbulence, and force expended to change the direction of momentum.
      Thankfully SL has great boatwrights like Qyv who worry about these issues! :-).
      xxx!

      • Bingo!
        I had a brief chance to test out the new Quest Scow, and of course Qyv is correct. I used default BWind settings, and sailed a 50 degree heading as I criss-crossed North Sea.
        Under those conditions the boat demonstrated a mild weather helm, deviating roughly six degrees windward after two minutes on a fixed course.
        The magnitude of helm shift will depend on many factors, so please don’t pay attention to that number. Nonetheless, the scow does seem to have a slight weather helm. It’s not enough to bother any sailor, but it emulates what you see in most RL single-sail boats.

        Qyv? Now, about that rudder thing…. 🙂

        Q-Scow weather helm

  6. Actually the weather helm stems from the difference between the location of the sailcenter and the center of lateral resistance. There is no rule or physical constraint saying single-sail boats have more weather helm. The simplest possible case is the Opti, where you swing the mast back (or forward) in order to adjust the location of the center of effort. More helm means more turbulence at the rudder, and that means more loss, so the optimum speed is reached at low helm. However, a slight weather helm is preferred because it makes it easier to steer at close hauled; More specifically it helps catching those lifts in the puffs. Most boats are able to be trimmed pretty much into neutral. Many standard bermuda rigged boats need adjustments on mast position, bottom and/or top, in order to get there. It’s almost always impossible to make a boat neutral on all wind angles, so usually focus is on close hauled balance.

    • Yup; no arguments. 🙂
      There are many ways to configure the layout of a boat
      or tune it’s rig to alter the helm bias.
      It’s part of the design,
      it’s part of the challenge,
      and hopefully,
      it’s part of the fun.
      🙂

  7. It sure is part of the fun. Setting up a boat to be in superior shape is so much part of the game. I just wanted to add the reasons for real helm; I felt it was missing here, because in SL boats it is not yet obvious what causes the helm, and it is not yet possible for the sailor to adjust things such as mastrake, length of front stay, tension of cap shrouds et.c.

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