Monthly Archives: April 2010

Cruiser Quiz Kids

  A week ago I quietly posted a fun picture from a sailing event, and asked if anyone could identify it. Kudos to Tory, Cate, and Manul for not only identifying the event, but also naming just about every sailor in the picture!!  


The photo was taken  at the start of the Mowry Bay Cruise on November 11, 2009. That evening a copious coterie of committed cruisers collected on the dock, eager to set sail once more. I admit I can’t even tell you where we ended up that night, but I’m absolutely certain everyone had a great time!!!  


I’m adding the ‘Answer Sheet’ for that Quiz Picture below, to confirm the guesses made by the three cruise directors. Wow, they certainly know their fleet!! (If you click the image below it will pop open so you can read all the sailors’ names.)  

Click to enlarge!

Click to Enlarge!

 And in case any of you have been in a coma recently, let me also comment that the Mowry Cruises are amazingly popular.  

David Wetherby sailing a Cotton Blossom

David Wetherby sailing a Cotton Blossom

Although Tory and Manul stepped down from their lead roles with MBCC a few months ago, the cruises they inspired continue to thrive with support from Blackbird Latte, Kittensusie Landar, Cate Foulsbane, Outdoorlover Galaxy and Chaos Mandelbrot, in addition to a long list of hosting clubs and marinas.

This week in fact there were two scheduled cruises on Sunday, and a third cruise on Tuesday. Despite that heavy schedule, the Tuesday cruise was so well attended the sim with the apres-cruise party (Sailors Cove’s Sailors Rest Clubhouse) was overfilled!!  With no exaggeration, I had to wait in line for more than 30 minutes just to get in!!


Great crowd and great cruise!

Thank you to Outdoorlover for leading the fleet, and thanks to Sailor’s Cove for hosting!!

Cruisers sail Mango Yacht Club

MBCC landing at Mango Yacht Club Last September

PHRF Numbers: A Classy Standard, With More Wild Boats!


Note: If you are a new sailor on the digital grid, let me apologize for the short article below.
It’s full of jargon, statistical terms, and obscure references.
Good Grief, it reads like a work memo!
Second Life Sailing’s PHRF is actually a lot of fun; it’s based on an old SL Sailing Hotlaps’ idea started by three very ‘real’ sailors: Cory Copeland, Cybrid Keats, and Kanker Greenacre (all smart skippers and all very funny people).
So…. if you are new to Hotlaps and PHRF, please don’t read this article!!  Instead, go read an Intro here.
You can then find a massive bibliography of links and posts on the history and updates to the SL-PHRF thing at the end of a recent article located here.
Actually that sounds too tedious… If any of that stuff in those articles sounds like you, please then come back here.
And if you’re a RL sailor and you don’t find what you’re looking for… no problems!
SL Sailing is a nice emulation of the real thing, and we have a global community waiting to cruise, race, or script the limits of your imagination…
If you have a question, just post a comment and ask! 🙂

 Last week I talked about  SL-PHRF numbers and posted a table of PHRF “handicaps” for a fairly large number of boats using the 2009 Madaket course. We switched to the “PHRF 2010 Course” on January 3rd, but I couldn’t report on those numbers at that time, since I thought it was important to change the “PHRF index standard.’ Based on the 2009 data, I thought the J-Class was the obvious choice as an Index Boat.

The ‘Index’ is the boat used for comparison; it’s a bit like like ‘par‘ in golf. The J-Class ‘average, good’ lap time on the 2010 test course arbitrarily gets a handicap of ‘1.00,’ and all the other boats are assigned handicap conversions relative to that number.  A boat with a handicap of “1.13” is thirteen percent faster than  the Index boat , and a boat with a handicap of  0.74′  is 26% slower.  The handicap conversion factors make it easy to level the playing field across a mixed fleet, at least with regard to solo lap times over the past few weeks. 

I commented last time that I needed 8-10 new J-Class data points to strengthen the ‘index’ for PHRF comparisons on the 2010 Course. Huge kudos to Trapez Breen and Chaos Mandelbrot for racking up thirteen new laps that fall right in a normally-distributed range, setting a basis for a new index. Norway and Texas fell dead-on the same statistical curve, volcano or not blocking their flight path! 🙂

Let me take a few sentences to comment on the choice of a new ‘index standard’ on the new test track.  The 2010 PHRF Course is roughly two sims longer than the 2009 course and in my opinion it is a better test track.
I guessed it would be perhaps 10% longer for most boats, given the extra distance and the  headings. Trapez and Chaos’ scores  came in a bit better! The new J-Class Lap time is 9.2% longer than 2009! Wow, the individual lap times and the time shift onto the new, longer course were close enough to endorse the J-Class as a new PHRF standard.  As we add more skippers and more data points in the next few months of course the baseline standard may shift appropriately; but this is a great start, with remarkably tight lap time- concurrence.

OK!!! In the first chart below, I repeat the 2009 scores through January 2, 2010. It shows the average lap times for the 2009 Madaket course, as well as the ‘corrected’ handicaps for all the boats sailed. Where available, the 2008 column shows earlier handicap data for a  large number of boats on several other test courses. There is pretty remarkable correlation over time and across multiple test scenarios.

Woots! OK the above table is closed, ended; it’s a dead-parrot.

We’re now switching to the 2010 course in an effort to demonstrate construct validity and reliability (we’ve done this as half-dozen times before). On the new course so far we have the Index boat scores, but we also have a total of 58 new test laps sailed on a variety of other boats!

Let me give a huge shout-out to Wally Warbaum, Colin Nemeth, Glorfindel Arrow, Francois Jacques, Lance Corrimal, Fearless Freenote, Trapez Breen, Aislinn Farella, Allie Tomsen, TaffyOcean Sommerstein, Slanty Uriza, Kembri Tomsen, Pensive Mission, Armano Xaris, Jane Fossett, Chaos Mandelbrot, Vin Mariani, and ahjep Kattun for running so many laps on the new 2010 course in a wide variety of boats.


At the moment I’m only reporting on a few boats; I’m waiting for the rest of the entries to reach statistical significance. However, if you are geeky enough, the numbers so far look pretty interesting! Although there are a few thousand  entries in the current database, there are only 58 valid laps on the current test course;  it will take several months to demonstrate the current results are consistent. 

Since we are changing the Index, for me the biggest question is whether the 2010 results correlate with the all the prior 2008-2009 lap info; actually, so far it looks pretty good!
For example, the  ACA33 v2.53 ranks a fast handicap score of 1.33, much faster than a J-Class but still slower than a Tako. That’s consistent with earlier ACA scores.

Even more accurate, the  WildWind RCJ-44 demonstrates an average lap time of 10:12, meriting a  handicap of 1.33; that’s a full 33% faster than a J-Class on the same course. More importantly, on the 2009 course the RCJ-44  earned a nearly identical ranking of 1.32, evidence the scores are valid and reliable year-to-year.

Given that very tight WildWind result, let me give a huge shout out to Orca Flotta and the entire sail team over at Triumphal; Woots!!!
They’ve logged a flood of new WildWind scores on the test track, adding several new boats to the list! Welcome to the SC22, SC 27, and SC35 v2.0!!!
And although there’s only one lap entry, let me send a shout out to Lance Corimmal for adding the TR-30!!!

Lots more to come soon!!!


Quick Quiz

Click the photo to enlarge!

Quick quiz!

Questions 1-12: Name the above-numbered sailors.
I hope I know nearly all of them, but when I switched viewer settings,
only 12 people had names over their heads! Can you name the twelve? 

Question 13: Where was the picture taken?

Question 14: What was the event?

Question 15: Why weren’t you there? 🙂

PHRF Update for 2009

On April 9, 2010, Chaos Mandelbrot posted:

April 9, 2010, J-class. This was my first time on the 2010 PHRF course with the J. Sim conditions were poor. Fractal came to a dead stop 3 times. Twice due to sim conditions. The third time was hitting a shoal just W of Indian rock. This course does not show off the J-class speed. The reaches are not at the optimal J-class angle. I suspect much slower boat speeds on this course than the previous PHRF course.

Thank you for your comment, Chaos! It’s about time I updated PHRF stuff!

In case anyone is unfamiliar with it, the PHRF Handicap project collects solo lap data from skippers who sail a simple, classic ‘test course.’ The results are automatically uploaded to a web database, and the data is then statistically filtered and pooled to determine an ‘average, good’  lap time for each class of boat under under the test, fixed conditions. It’s easy and it’s fun, and any skipper can try it out any time they want, in any boat they choose. Since everything is always the same, sailors can use the Madaket course to sharpen their skills, try new things out, and document the changes over time.

The pooled information over the past 26 months involved nearly a hundred individual skippers who sailed several dozen boat classes on eight different race courses. Ocean Racers (click to enlarge)Those efforts generated a few thousand ‘valid lap score’ entries. That robust database makes it possible to calculate ongoing valid and reliable ‘handicap factors’ that compare  the average performance of different boats that sail in SL. I posted the most recent handicap update in November 2009; that post includes a bibliography of many prior articles that discuss the handicap system, and should answer just about any question.

For most of 2009, the PHRF course started in Madaket and followed a route that included equally-sized beat, run, and reach legs, using the buoys in Cannonade and Flotsom as marks (see the charts below). On January 3, 2010 however, the Cannonade yellow mark moved to Howser; that forced an official close to the 2009 PHRF test course. Actually, that was no big deal, given the large amount of data already collected; it was time for a new course anyway!

The new “PHRF Hotlaps 2010” course uses the rock in north-central Indian sim as the upwind mark; it stretches the upwind/downind leg an extra twenty percent or so. It also does something a lot more important; if you look at the 2009 course below, it has two “Reach” legs from the yellow mark to green, and then back again. Those two tacks on the 2009 chart are beam reaches, and they only test performance on a single  boat heading. M1sha Dallin pointed this out many months ago, and I think she’s right, the course could be better.

The new ‘2010’ course shown below fixes this problem, at least to a small degree. The angle between Indian Island and the Green Mark turn those legs into a close reach and a broad reach, and hence make the course — potentially — a better test track. Having said that, I must admit that every course we tried over the past two years produced near-identical performance rankings, evidence that the results are valid, reliable, and ‘portable’ to other courses.

2009 and 2010 Madaket PHRF Courses

Chaos stated above: “This course does not show off the J-class speed. The reaches are not at the optimal J-class angle. I suspect much slower boat speeds on this course than the previous PHRF course.”  I admit that Chaos may well be correct, the new ‘2010’ course might not be ideal for J-Classic.  In fact, I hope it’s not; that’s not the intention.  The PHRF course is just intended as a simple, quick, and ‘fair’ test of  a boat’s basic sailing performance. It shouldn’t be tuned to the advantage of any particular boat.

Having said that, let me get back on topic here and post the ‘final’ update on PHRF scores for the 2009 course; the summary table below includes handicap adjustments based on all valid laps sailed prior to the switch on January 3, 2010:

The left column lists the name of the boat, and the second column lists that boat’s ‘average good lap time’  for the 2009 PHRF course shown above. To generate a simple performance handicap score, two years ago we chose the ‘Trucordia Yawl’ as an index boat, since it was popular and its lap speed was in the middle of the pack. A given boat’s ‘handicap’ was defined as a simple ratio: [Yawl Average Good Lap Time] divided by [Test Boat Average Good Lap Time]. That ratio repeatedly demonstrated that a boat like the Tako was 30-35% faster than the index Yawl, while the Trudeau Tradewind proved 47-55% slower. The 2009 handicaps are listed in blue in the third column, and the fourth column shows the 2008 handicaps, where available.

 The latest summary numbers above don’t show any new surprises. That should be reassuring, and actually pretty consistent with sailors’ predictions. For example, I commented many weeks ago that the Trudeau Columbia handled much like a J-Class, with a few extra features thrown in.  The latest numbers reveal a J-Class handicap of 1.00, while Columbia scores a 0.99.   I’d say that was pretty close!

I think I’ll stop commenting there however, because I still have a few months’ worth of  numbers to look at, based on the new ‘Hotlaps 2010’ race course. But before I can post those scores, I think it’s important to change the index boat!

As I mentioned above, for two years I’ve been comparing everything to a Trucordia Yawl. That boat uses a Real Wind engine, similar to the original Tako. It was highly appropriate many months ago, but these days most boats (including all modern Trudeaus) use Apparent Wind algorithms to power the sails. I think it makes sense to switch to an index boat that uses Apparent Wind.

I originally thought to use the Trudeau Twenty or even the Knockabout as an Index. However, after looking at the most recent numbers, I changed my mind. There are seventy-seven J-Class data laps for the 2009 course, and the J-Class Handicap ended up a perfect “1.00.”

 However, I can’t recalculate the last three month’s data on the new Madaket 2010 Hotlaps course until I get more J-Class lap scores. As soon as I get a few more laps from different people (I need a total of maybe only ten more), the rest of the numbers should fall in place and I can post another updated table incorporating the modern index.

How geeky is that? 🙂


Sailing Straight: Two Boats With a Lee Helm

Not too long ago I wrote excitedly about two new, free Tako-based boats: the BBK 137 and Nemo Nantucket. The boats differ in both their concept and construction, and I thought it was pretty fantastic that Kanker’s original ideas might live on in the creativity and enthusiasm of a new generation of boatbuilders.

While testing out those boats, I noticed that Nemo had a “Lee Helm.” It’s a small point, but this issue comes up in real life too and it may partly explain some of Nemo’s behavior, so I thought I’d mention it here.

First, to introduce the topic, let’s talk about helm ‘balance!

A Balanced Helm

JG-44 30R holds a course

When they try out a new boat in real life, many sailors will check how “balanced” the boast’s helm feels on different points of sail. After all, as Ben Franklin said, “A helm unbalanced is not worth sailing.” (or maybe that was Socrates… 🙂 )

Anywayz, a well-designed and well-rigged boat should feel at home on all major points of sail; if you set a heading of 40°, the boat should ‘dig-in’ and hold that course without much complaining.

Quite often however, boats end up unbalanced and consistently drift off course. The most common example of this is called a weather helm, where a boat sailing upwind continually wants to head higher into the wind; it tries to “sail to weather”.  A  skipper needs to constantly apply leeward pressure to the wheel or tiller to hold a ‘weather helm’ boat on a constant compass course. This is only a small irritation on leisurely weekend cruises, of course, but it can become a real pain in races when strong foul weather gusts dramatically amplify the forces on the boat. I’ve sailed races where I had to give up the helm because I didn’t weigh enough to control the boat; the weather forces transmitted to the helm kept lifting me in the air while I tried to hold the boat on course.

Luckily, most boats in SL are nicely balanced. You can set a compass heading, raise sail and let go of the wheel; the boat will faithfully hold it’s course. That’s good news, since most skippers end up busy enough sheeting to the apparent wind changes, switching the sails, reefing, and much, much more.

Click to enlarge

To illustrate this, I’ve added some images above from an Oceanis 160 on a beam reach; the Oceanis 160 is a good example of a BWIND boat with nice balance.  It’s also an easy boat to test, since it has multiple, detailed displays.

Using wind from the North at 15 kn, the first image in the figure above shows the boat heading directly East at a bare 1.63 kn.

JG-44 on beam reach; Wind dial shows AWA adjustment

That results in a real wind angle (RWA)= 90° and an apparent wind angle (AWA)= 84°, as shown. If you then trim the sails without touching the helm or changing course, the boat picks up speed and the  apparent wind direction appropriately shifts toward the bow (AWA= 55° in the middle frame above). After many minutes of sailing without changing the original heading, you can then drop sail and confidently find yourself on the exact compass course you originally set. Oceanis 160 uses BWIND brains for helm balance,  and the boat holds its own, sailing straight as an arrow… quite nicely, in fact.

Good balance is, of course, not a trait exclusive to BWIND or Oceanis.

I’m gradually going through the whole list of popular sailing vessels in  SL, and every boat so far in the Trudeau Fleet  and Juli Designs’ lineup shows a “straight-down-the-line balance.” If you set a course and take your hands off the wheel in these boats, they remain compass-true.

By the way, you can also add the Wildwind Fleet to the ‘balanced boat bunch’ too; I ran my JMO-60 through it’s paces, and got no more than a 2° fluctuation in heading while sailing a fixed course for three minutes. 

Two For the Lee Road

Ok, so my point above is that the large majority of sailboats in Second Life have what might be called ‘a balanced helm.‘ You can set a compass course and take your hands off the wheel;  your boat will sail true.

 This may seem like a small point, and you might even think it’s a pretty obvious one.  However, I’m bringing it up  here because there are two popular boats, the Tako 3.3 and the Nemo-N/R, that appear off-balance and seem to have a ‘Lee helm;’ If you set a course heading, these boats won’t sail a straight line; they sail an arc that gradually turns the boat away from the source of the wind. A skipper needs to invest extra time and tiller touch-ups to stay on tack.

Let me show you what I mean :

In the figure below I set my Tako on a beam reach (RWA=  89°) with a compass heading of  270°.  After sailing for nearly 4 minutes without touching the tiller or changing the heading, the boat had spontaneously turned 11° away from the wind.

Click to enlarge

Is an 11° deviance in four minutes a lot?  That’s for you to judge and it certainly depends on the context, but let me make these comments in that regard:

  • Columbus, Magellan and Cook would still be sailing slow circles in European harbors if they were even 1/1,000 so inaccurate 🙂 ;
  • Any Tako racer knows that even a 2° difference on close haul, say from 34°-36°, can have an enormous impact on boat performance;
  • None of the other boats mentioned above showed any helm preference, so it’s not an ‘artifact’ of the sims or system; and
  • Although a beam reach is a “special” point-of-sail for the Tako (the spinnaker inflates on that heading), the downwind drift appears to happen at all points of sail; its intrinsic to the boat and its power algorithm, not to any specific heading.

Behavioral Genetics

The recently-released Nemo-N/R has a similar Lee Helm propensity.

The figure below shows a series of six sequential Nemo images, while sailing a fixed course with the default 15 kn wind.

If you look at the circular guage, you can see the blue indicator shows the boat starting on a beam reach, with an approximate wind heading of 90°.

 As the boat picks up speed, look carefully at the next four frames. Even with a boat speed of 7.0 kn ( half the true wind), the blue indicator for wind angle stays locked at just about 90°.

 That looks like the Real Wind heading, not “Apparent Wind.”  Two weeks ago I concluded that Nemo’s sailing engine must be using a ‘Real Wind’ algorithm. Nomad Zamani (the boat’s  scripter) corrected me, however, revealing that the boat did use apparent wind, albeit an attenuated version of it (Apparent Wind Lite?).  I was sort of ‘flummoxed’ with that info, since I couldn’t show any upwind velocity-based angular wind swing toward the bow in Nemo (the definition of ‘Apparent Wind’).

It turns out Nemo’s Lee Helm may explain why ( at least in part).  

Click to enlarge

Take a look at the orange arrows in each of the frames above.  They indicated a fixed reference, the clock over the raceline in Farragut. When the boat’s at rest in the first image of the sequence, the bow is pointing slightly starboard of the clock. In each of the following frames, however, the boat’s heading falls further leeward and further to the port side of that heading relative to the clock.

That may explain the Apparent Wind confusion in the prior Nemo discussions; I didn’t appreciate Nemo couldn’t hold a heading. One reason Apparent Wind doesnt show the typical shift toward the bow in Nemo seems to be that Nemo wants to turn away from the wind; it’s heading spontaneously rotates downwind. The size of that angular fall-off is roughly equal to the maximum adjusted wind angle change (AWA) in the boat.

If you’re confused by this, so am I :-), I’m still looking at it, and I’m posting here to get more input and ideas. Hey, but don’t worry :-), the ‘Trouble with Nemo’ seems similar to what happens in the Tako, and that can’t be too bad. We all know that little unruly Tako showed it had the right stuff.

It proved to be the inspiration that lit the fuse for everything else in SL Sailing over the past four years.

So, that lee helm thing? It’s not a defect, it’s not a flaw…

It’s just personality!