A new Comfort Ratio

[Zzmeyer]

Ted Brewer developed a “comfort ratio” to help determine the comfort of water sailing">blue water sailing. It has been used to bash modern boats for years. It is, as I think he would admit, flawed. The formula essentially rewards displacement and narrow beam. Looking at two boats for example, the Passport 40, a classic blue water cruiser has a comfort ratio of 33.96 while the modern Jeanneau 410, at almost the identical length, has a rather dismal comfort ratio of 22.57. The Jeanneau has a waterline length almost 4.5 feet longer than the Passport and a beam a half a foot wider providing significantly more room and displacement some 5,500 pounds less. Using the “comfort ratio” the Jeanneau could increase its comfort ratio to that of the Passport by simply decreasing the beam by about 3.5 feet to 9.7 feet. Hogwash!
I’ve developed a new measure of comfort at sea. I call it “ICE” or Improved Comfort Equation. It is boat length times 1 if sailing downwind and down current and times 0 if going upwind and up current. I’ve owned 10 boats of which three I’ve sailed more than 1,000 miles non stop. A 33 foot Santa Cruz, a 42 foot Jeanneau and a 50 foot Beneteau. While all three were comfortable sailing downwind from San Diego to Puerto Vallarta, the bigger the boat the more comfortable it was. A bigger, more stable platform for sailing, sleeping, eating and relaxing. Having brought them North against the wind and current none were comfortable. At the halfway point one year I chatted with the crew of a Pacific Seacraft 40 and they confirmed bashing to weather is uncomfortable. So my formula rates the 50 footer, 42 footer and 33 footer as 50, 42 and 33 on the ICE schedule going downwind and they all rate 0 going against the wind and current. Very consistent with my observation. I debated adding another factor, the crew factor, where a amiable crew multiplied the result by 2 and a group of jerks multiplied the results by 0, but decided to go with simplicity.
Are there other formulas you think are flawed or have you developed other formulas which can help in selecting one’s next boat?

[StuM]

Originally Posted by Zzmeyer

Ted Brewer developed a “comfort ratio” to help determine the comfort of blue water sailing. It has been used to bash modern boats for years. It is, as I think he would admit, flawed.

Bear in mind Ted's words:
COMFORT RATIO (CR): This is a ratio that I dreamed up, tongue-in-cheek,

I call it “ICE” or Improved Comfort Equation. It is boat length times 1 if sailing downwind and down current and times 0 if going upwind and up current.

Seems reasonable to me - but maybe I'd go with the square of the waterline length multiplied by your directional factors A forty/sixty footer is a lot more than just twice as comfortable as a twenty/thirty footer

[Island Time O25]

All the boats I've been on corresponded roughly to the comfort ratio formula. Can't understand what's the fuss is about unless you own of of the lower number specimen.

[Mike OReilly]

It's interesting how people always quote Brewer's first part of his comment about this ratio, but always fail to finish his sentence. What he actually says is:

This is a ratio that I dreamed up, tongue-in-cheek, as a measure of motion comfort, but it has been widely accepted and, indeed, does provide a reasonable comparison between yachts of similar type.

Reading the whole sentence puts his thoughts on this ratio in a bit of a different light than is typically presented.

If you want to read his entire description of this calculation you can do so here: https://www.tedbrewer.com/yachtdesign.html

Comfort is by its nature a subjective concept. But as Brewer actually writes, "[Comfort ratio] is based on the fact that the faster the motion the more upsetting it is to the average person."

Like all these ratios, they're not meant to be taken as some sort of definitive statement about a boat. But like IT says, it roughly corresponds to my experience sailing different types of keel boats.

[daletournier]

Speed! Spending 3 less nights at sea greatly adds to comfort.
On long passages that extra 1kt+ makes a huge difference and quite often that extra speed alters the ride to favor comfort.
Bigger modern boats with wide bums are more comfortable than older narrower boats imho, I've owned and cruised both.

[Mike OReilly]

Originally Posted by daletournier

Speed! Spending 3 less nights at sea greatly adds to comfort.
On long passages that extra 1kt+ makes a huge difference and quite often that extra speed alters the ride to favor comfort.
Bigger modern boats with wide bums are more comfortable than older narrower boats imho, I've owned and cruised both.

I'd humbly suggest you're pioneering a wholly different factor; perhaps call it the Passage Misery Index: PMI .

Of course, if fewer number of nights on passage is the measure, the best option is an airplane , or even a cruise ship.

Or, just go for longer. Size matters for speed, so longer LWL is going to be faster, and better on this new PMI scale. It will also be better on the Comfort Ratio scale as well.

[deblen]

Comfort-it's relative.

https://www.youtube.com/watch?v=582ztxCQM-8

[Mike OReilly]

Originally Posted by deblen

Comfort-it's relative.

[John DeLong]

Comfort is directly related to acceleration. With accelerometers widely available as phone apps data might be compiled including sea state, point of sail, sail plan and make & model of boat - location of the phone might also be noted. With enough submissions a database could be constructed and Brewer's and other "comfort ratios" could be assessed and evaluated. Data for a particular model could allow a captain to evaluate her loading, sail plan and improve polars. Maybe Noonsite or CF would facilitate uploading of dynamic acceleration and associated metrics data. Thoughts?

[StuM]

Originally Posted by John DeLong

Thoughts?

My thougt is that a lot of people are sadly lacking in their ability to detect humour


Maybe I should point out that under the proposal every vessel has a comfort ratio of 0 when sailing into wind

[Knotical]

Originally Posted by Zzmeyer

the bigger the boat the more comfortable it was.

If the bottom line is this then why do we need a formula?

[John DeLong]

Originally Posted by StuM

My thougt is that a lot of people are sadly lacking in their ability to detect humour


Maybe I should point out that under the proposal every vessel has a comfort ratio of 0 when sailing into wind

Well okay... The math is clear, and clearly presented in a playful manner. The interest in comfort ratios and practical assessments of a boat's handling characteristics and sea kindliness are of keen interest to many - me included. I suggested that the widespread availability of accelerometers could be used to provide more comprehensive and useful data to address this - and move us beyond rough estimations and statements of the obvious. I suspect my proposal would confirm a comfort level of 'O' for going to windward - but it would be significantly more useful at measuring comfort at any other point of sail. Thoughts?

[DMF Sailing]

Originally Posted by deblen

Comfort-it's relative.

I was going to reignite another running CF debate by commenting "Is that your motorsailer in the foreground?," but I decided not to

[Mike OReilly]

Originally Posted by Knotical

If the bottom line is this then why do we need a formula?

Because size isn't the only factor. It's significant, but there other parameters that contribute. That's what these formulae try to get at.

But again, none of this should be taken too seriously. A boat is more than the sum of its stats. It's an interesting, and somewhat useful way of comparing similar styles of boats. That's all.

[deblen]

Originally Posted by DMF Sailing

I was going to reignite another running CF debate by commenting "Is that your motorsailer in the foreground?," but I decided not to

No-just some N.S. lobster boats in "comfort testing" conditions.
The lead boat is a 2 napkin & the second is a new improved model that appears to be approaching one napkin in comfort.
Comfort is measured by the number of wet napkins that it takes to keep your coffee cup on the table.