Is your boat QUICK??

[Jackdaw]

Several current, related threads on boat speed and performance has prompted several forum members to reach out to me and ask my thoughts on boat performance, polars, and if their boat was 'fast'. After responding and a bit of thought, maybe I've come up with a generalized answer. I'd be interested in everyone's thoughts.

First of all, I think it's better to think about a performance in terms of 'quick', and not 'fast'. Overall top speed, or 'fast' is largely a function of hull/LWL length and wind speed, and is not a great performance measure. So we have to look elsewhere.

We also have to factor on size. As mentioned above, a boat's speed potential through the water is a function of length, so performance will be relative to that.

But even if we factor in length, what is a true measure of performance? We know its not a beam reach in 12 knots, because every boat will feel 'fast' them.

When I was on the Ski Team, I had a coach who had a favorite saying... he said; 'Making turns where you want to is easy. Making turns where you have to is hard.'

Very true, and there is a corollary in sailing. Sailing where you want to is easy. Sailing where you have to is hard.

That's why I like to look to PHRF racing performance numbers as an indication of how 'quick' a boat is. These handicap numbers measure a boat's capability to sail where it does not want to go; ie, straight upwind and downwind in all ranges of wind speed. The difference between any two boat's numbers are the number of seconds one will sail a mile faster on the racecourse. So the smaller the number is, the 'quicker' the boat is. By factoring boats from all over the USA, US Sailing uses a large base of boats to get a accurate picture of every boat. It's not perfect, but its very good.

But back to our question... what IS quick? And remember we have to factor in length. To start to create an answer, I built up a table of quick-boat PHRF numbers based on length. To try and get a sense of what a quick 'control' boat would be, I used all the J/boats and the First series in the range of 21 to 35 feet, and averaged them where possible. The results are shown below.

Its clear that each range has its very fast boats, and some slower and more 'cruisy'. But the range follows the slope of the linear line which plots each foot knocking 8.3 seconds off a boat's time/mile. The only big exception is at 28 feet, where both ranges have a slower cruiser model.

So, I put forward that if your boat's PHRF number is in the area of the CURVE or AVERAGE number based on length, its a quick boat. Lower and you are very quick. Higher and you are slower, and more cruisy.

Now, even if you do not race, there are real world applications. In general, a boat that has a lower PHRF number for its size will sail better. It will turn faster, accelerate faster, go to weather better, and do better in light airs.

You can find your average PHRF number for your boat here:
http://www.ussailing.org/wp-content...Current Base Handicap Class Hi Lo Average.pdf


This of course is for non-planing keelboats with in-cabin accommodations. And one size does not fit all.

Thoughts?

 

[Scott T-Bird]

Why select the quickest boats to base the curve?

The curve probably loses relevance when the curve is based on a tiny selection of specialty boats. For instance, looking at the vast selection of boats in the 27' range with PHRF numbers, probably 95% of them have a number somewhere around 200, but according to this curve, an "average" for a quick boat would be about 140. In fact, can you actually find a boat that would be considered quick? It's probably a very select group of specialty boats.

So it isn't really meaningful to compare the vast majority of boats to this number. It's just a confirmation that the vast majority aren't specialty race boats. The curve would be better suited to compare boats when it is based on a broader average, or an average of similar boat design. A full-keeled boat isn't going to be quick by any stretch of the imagination when compared to a fin-keeled race design.

Also, it would be more interesting to note PHRF numbers relative to LWL rather than LOA.

 

[Jackdaw]

The curve probably loses relevance when the curve is based on a tiny selection of specialty boats. For instance, looking at the vast selection of boats in the 27' range with PHRF numbers, probably 95% of them have a number somewhere around 200, but according to this curve, an "average" for a quick boat would be about 140. In fact, can you actually find a boat that would be considered quick? It's probably a very select group of specialty boats.

So it isn't really meaningful to compare the vast majority of boats to this number. It's just a confirmation that the vast majority aren't specialty race boats. The curve would be better suited to compare boats when it is based on a broader average, or an average of similar boat design. A full-keeled boat isn't going to be quick by any stretch of the imagination when compared to a fin-keeled race design.

Also, it would be more interesting to note PHRF numbers relative to LWL rather than LOA.

Scott,

For sure, the trick is to pick something that makes sense as QUICK. The average on the charts is the average rating of the J and First of that size. It seemed like a good place to start.

As for length, I feel that the measured distance of a boat when it comes to speed ends up best being somewhere between the HULL length and the LWL. When heeled at speed, the actual waterline length increases to somewhere between these two numbers. I chose to use hull length because it was easy. Anyway a good designer designs boats to maximize overall speed with this factored in anyway.

 

[kloudie1]

I think it is a good presentation, Jackdaw. Sort of shows the upper limits at hull length so by going to the USYRU ... eerrrrr US SAILING list, one can see quickly where a boat sits compared to the really quick ones.. if one were trying to select amongst boats and desired it to be kinda "cruisy" but quicker than others of similar design, one could quickly see the upper limit and then pick closer to or further from that number.

 

[Jackdaw]

I think it is a good presentation, Jackdaw. Sort of shows the upper limits at hull length so by going to the USYRU ... eerrrrr US SAILING list, one can see quickly where a boat sits compared to the really quick ones.. if one were trying to select amongst boats and desired it to be kinda "cruisy" but quicker than others of similar design, one could quickly see the upper limit and then pick closer to or further from that number.

That's soft of what happens. All of the boats on the list are 'cruisable', but some clearly more than others. The two 27 footers are very quick but cramped; the 28 footers are clearly more cruiser.

BTW the way these boats are by no means at the upper limits quick-wise; I know of much faster keelboats at all of these lengths. But the J and Firsts are common product boats.

The basic calculus here is that the features that make a boat comfortable typically make it slower, and quick features are expensive. In a world where the average sailor (and SO!) wants something comfortable, roomy, and inexpensive, that boat always ends up being slower than a more focused boat.

 

[thinwater]

That's soft of what happens. All of the boats on the list are 'cruisable', but some clearly more than others. The two 27 footers are very quick but cramped; the 28 footers are clearly more cruiser.

BTW the way these boats are by no means at the upper limits quick-wise; I know of much faster keelboats at all of these lengths. But the J and Firsts are common product boats.

The basic calculus here is that the features that make a boat comfortable typically make it slower, and quick features are expensive. In a world where the average sailor (and SO!) wants something comfortable, roomy, and inexpensive, that boat always ends up being slower than a more focused boat.

How many J-boats are loaded for cruising? Full tanks, dingy, spares, full pots and pans etc? It's well known that racy classes carry tough numbers, whereas some cruising classes, if stripped bare (no more stripped than a J-boat) and bottom faired beat ratings easily.

I used to cruise a Stiletto 27, sometimes for weeks. Very fast, over 20 knots on a reach in the right breeze, but few would consider it cruiseble. Few would consider and open 60 cruiseable, but in some sence, they do.

A strange exersize.

 

[Jackdaw]

How many J-boats are loaded for cruising? Full tanks, dingy, spares, full pots and pans etc? It's well known that racy classes carry tough numbers, whereas some cruising classes, if stripped bare (no more stripped than a J-boat) and bottom faired beat ratings easily.

I used to cruise a Stiletto 27, sometimes for weeks. Very fast, over 20 knots on a reach in the right breeze, but few would consider it cruiseble. Few would consider and open 60 cruiseable, but in some sence, they do.

A strange exersize.

Anything carried to the extreme becomes nonsensical. But that does not dis-prove the basic premise. The fact is 90% of all sailing is day sailing or weekend cruising. The boats listed fit inside that margin, along with 95% of the boats owned by people on this board. Outside of that you start looking at specialized boats, and the goalposts change.

If you DO bluewater cruise, your definition what what quick is probably changes. Or becomes unimportant. If is does not, do the trip in a J/120.

 

[thinwater]

No, I don't think that most of the boats raced fit the cruiser definition, with minimal loads. They may not all be specialized, but the point is handicap values are based not on average boat, but on those sailed well, which invariably means light. The cabinets arn't full and you see few J-boats with davits. There is a bias in the numbers that is correct for racing, but is unavoidable. Just be aware that it is there.

I'm also not certain I buy the windward/leeward course as an all around measure. It is one valid measure, no question, but cruising, in my expereince, is mostly reaching, with some weather and DDW work as well. if it was all beat/run, they wouldn't sell many reachers and wouldn't need outside jib tracks.

But it's a fun thread. I get the "quick" feel thing; I've always enjoyed sailing small boats most.

 

[Gary_H]

Quick ...no my boat is built for cruising not racing, The fastest I've had her is 8 knots with wind and tide in my favor. She responds to the controls in a timely manner but not what I would call quick.

 

[Anonymous 121765]

These are the type of threads I like.
So, allow me to deviate from the formula speed stuff, to add some thought to the mix.

My boss had a J-boat & did alot of racing. It was a very quick boat compared to the mix of boats he raced. However, besides the speed formulas there are some additional factors when talking speed/quickness.

I'm speaking in a general sense here regarding open class racing. Yea, boat quickness and/or speed are the first factors to take into account. Then there are the intangible factors, which are difficult to add to the formulas.

Depending on the many different regattas, additional factors for speed & quickness would also have to include to how good are the Helmsman, Skipper, Tactician, Main trimmer, Port Trimmer, Starboard Trimmer, Pitman & Bowman etc. What too are the differences in sails & sail plan layouts? All, are not created equal. These factors will change the formulas on a boat by boat basis.

Take Dennis Connor for instance. I watched his blunders for years, he had the quicker on-paper boats but, because he was not that good a skipper/tactician, found his boat performed slower than the formula.

CR

 

[rgranger]

My boat has a PRF of 219.... (Balboa 26) so I guess I'm slow. But out on the lake, I usually pass other sailboats. So I guess I'm okay with slow.

 

[trainmanjess]

hello all

my boat has an average PHRF rating of 270, but I still sail faster and pass up lots of boats in the races.... I cannot out sail the J boats, or the other racers, but with my PHRF rating I give them a run for their money....

the other day on the race, I passed up a capri 22, hunter 240, hunter 260, and a catalina 23.... I beat all 4 boats at the race.... I felt I got lucky... I am not usually a racer of my own boat... I usually race on a friends boat....

my boat is a coastal cruiser, full keel boat.... '67 Kittiwake 23'... nice cruiser, heavy keel...

sincerely
Jess

 

[Anonymous 121765]

Train,

I believe you added fodder to my earlier post man.

Thank you,

CR

 

[All U Get]

When I was younger I always wanted to be fast, but now that I'm older "half fast" is a fact of life.

All U Get

 

[Kings Gambit]

But back to our question... what IS quick? And remember we have to factor in length. To start to create an answer, I built up a table of quick-boat PHRF numbers based on length. To try and get a sense of what a quick 'control' boat would be, I used all the J/boats and the First series in the range of 21 to 35 feet, and averaged them where possible. The results are shown below.

It's clear that each range has its very fast boats, and some slower and more 'cruisy'. But the range follows the slope of the linear line which plots each foot knocking 8.3 seconds off a boat's time/mile. The only big exception is at 28 feet, where both ranges have a slower cruiser model.

So, I put forward that if your boat's PHRF number is in the area of the CURVE or AVERAGE number based on length, it's a quick boat. Lower and you are very quick. Higher and you are slower, and more cruisy.

Now, even if you do not race, there are real world applications. In general, a boat that has a lower PHRF number for its size will sail better. It will turn faster, accelerate faster, go to weather better, and do better in light airs.

The PHRF (Performance Handicap Racing Fleet) system certainly has its drawbacks when applied widely over the full range of sailboat types. That's why separate PHRF classes are established; so boats of similar (rather than dissimilar) type compete against each other. You might say---so the "quick" boats may compete against other "quick" boats, etc. For example, a separate class for ULDB's. This would be true even if the PHRF ratings of the ULDB's overlapped the range of ratings of another class that were not ULDB's.

So, we essentially have a system for sorting out boats as to their "quickness", it's just not based directly on length or PHRF rating. It's based on the SA/DPL (sail area/displacement) ratio. When that ratio is high (> 22) the boats would be classified very quick racers; < 15-as heavy cruisers, etc. Boats of different lengths can have similar SA/DPL. The ratios for a J-30 and a J-35 are in the range 19.46-19.24 but due to their different LWLs of 25 vs 30 ft, their PHRFs are 138 vs 90, respectively. If you standardize [control] the curves to represent separate bins of boats based on SA/DPL and then run the regression of PHRF vs LWL you'll knock out some of the variance introduced by the "cruisy" types in the mix. LWL is better b/c LOA based on the model class is not a true measurement of length. If you wanted to use the measured LOA, it might work as well as LWL.

For a few racing-type boats in the bin of SA/DPL values between 19.1 & 20.0, where PHRF is regressed on LWL, you should have a much "straighter" line. If you enter your boat with that SA/DPL and it does not fall near the line, then either your boat is not as quick as it could or should be relative to the others forming that line (far above); or you have a rating GIFT (far below)!!

 

[shemandr]

... I cannot out sail the J boats, or the other racers, but with my PHRF rating I give them a run for their money....

That's the point of a rating system, isn't it? I think if you're giving the J-boats "A run for their money," your fleet handicapper is doing a good job!

 

[Jackdaw]

That's the point of a rating system, isn't it? I think if you're giving the J-boats "A run for their money," your fleet handicapper is doing a good job!

Exactly. And if you are beating them, you're a better sailor!

 

[Jackdaw]

The PHRF (Performance Handicap Racing Fleet) system certainly has its drawbacks when applied widely over the full range of sailboat types. That's why separate PHRF classes are established; so boats of similar (rather than dissimilar) type compete against each other. You might say---so the "quick" boats may compete against other "quick" boats, etc. For example, a separate class for ULDB's. This would be true even if the PHRF of the ULDB's overlapped the range of PHRF's of another class that were not ULDB's.

So, we essentially have a system for sorting out boats as to their "quickness", it's just not based directly on length or PHRF rating. It's based on the SA/DPL (sail area/displacement) ratio. When that ratio is high (> 22) the boats would be classified very quick racers; < 15-as heavy cruisers, etc. Boats of different lengths can have similar SA/DPL. The ratios for a J-30 and a J-35 are in the range 19.46-19.24 but due to their different LWLs of 25 vs 30 ft, their PHRFs are 138 vs 90, respectively. If you standardize [control] the curves to represent separate bins of boats based on SA/DPL and then run the regression of PHRF vs LWL you'll knock out some of the variance introduced by the "cruisy" types in the mix. LWL is better b/c LOA based on the model class is not a true measurement of length. If you wanted use the measured LOA, it might work as well as LWL.

For a few racing-type boats in the bin of SA/DPL values between 19.1 & 20.0, where PHRF is regressed on LWL, you should have a much "straighter" line. If you enter your boat with that SA/DPL and it does not fall near the line, then either your boat is not as quick as it could or should be relative to the others forming that line (far above); or you have a rating GIFT (far below)!!

Great reply.

I've found banding useful because it breaks boats into like fleets that do better (or worse) than their number based on conditions as a class. Sport boats are a great example. So are 'slower' cruisers in reaching races. Our 36.7 is only 35 feet long but sports a PHRF 75. We have several 40 foot cruisers (a tartan and a C&C) that rate 110 that merrily sail right next to us in a reaching race if the wind is up. If there is no big upwind section that allows us to pull away, they crush us corrected. PHRF racing.

Net-net, one-number system are often off.

 

[shemandr]

I've found banding useful because it breaks boats into like fleets that do better (or worse) than their number based on conditions as a class.

Yes! In our upcoming "Whitebread XXI" regatta we will have 12 or 13 starting divisions spread over 4 or 5 starts. The average number of contestants in each division will be 9 or 10. It's not that we like giving out trophies (We do), but with the variety of boats entering, and we don't limit the PHRF, you have to use banding. Still there turn out to be odd bedfellows.
And to have each class sail in the same race with regard to changing tide and wind conditions, they need to be together on the racecourse. Otherwise, the validity of the PHRF number goes out the window.

 

[thinwater]

Exactly. And if you are beating them, you're a better sailor!

No, you still don't get it. Reread King's post. Fast boats are typically more difficult to sail to their rating, because the rating is based on racers and often better sailors! Cruisers are often fully loaded and sailed by mom and pop crews. Put a pro crew in in a stripped cruiser in you will clean up a handicap field, like cheating. It is much more difficult to dominate a puer race class.

And there are other problems. For example, performace multihulls don't handicap well with monohulls. It is not just that they are often faster; their speed envelope is different, favored by winds that will drive them over hull speed and smoother water. In light winds, beating, they suffer. Off the wind in a breeze, or even full and by, see ya.

I only ever enjoyed one-design racing. No BS, you finished well, or you didn't.