Making sense of calculations and PHRF ratings
Posted by Huckleberry181@reddit | sailing | View on Reddit | 36 comments
How important are calculations to you when looking for a new boat? Which ones, and why?
I'm currently looking at a Tanzer 26 & a Cape Dory 28.
By the #s, the Tanzer should be much faster, but I've read that the Tanzer is slow while the Cape Dory is "surprisingly quick." PHRF ratings are very similar despite the displacement, S/A, and S# being significantly different. I get the CD is slightly longer, but wouldn't think 2' would help THAT much.
PHRF of Tanzer is 216-222, CD is around 220 as well.
S/A is \~17 vs 15
S# is 3.13 vs 1.18
The Tanzer also has a low comfort ratio of 16, but I've read that they're stable tanks built for Superior and the other Great Lakes.. how do the two go together?
Do those #s not mean that much in the real world? I've read that both win races, and while racing is not my focus at all, a good handling boat is.
Free_Range_Lobster@reddit
If you're not racing, PHRF ratings are meaningless and have no relevance to how well a boat handles.Â
Huckleberry181@reddit (OP)
How does a racing handicap not have relevance for how a boat handles? A boat quicker around the buoys will have a lower rating, no? I'm confused as to how a boat approx double the weight and with much lower #s across the board can have such a similar rating there.
Free_Range_Lobster@reddit
It's a calculated number based on ideal conditions then adjusted against historical racing results if there's enough results. There's many boats that absolutely cannot be sailed to their rating.
Huckleberry181@reddit (OP)
I'm aware, but if they couldn't be sailed to their ratings then they wouldn't be winning races either. 🤷
the-montser@reddit
Boats that can’t sail to their rating aren’t winning races.
Huckleberry181@reddit (OP)
That's what I said. What boat are you referring to that can't sail to its rating? Both of the boats in question do win races, so both can be sailed to their rating.
Free_Range_Lobster@reddit
Where?
Huckleberry181@reddit (OP)
Check out the Cape Dory forums, plenty of people claiming there to win some, and I have no reason to doubt them.
H0LD_FAST@reddit
If you race a slow, easy to handle highly rated boat like a cape dory against a j24, you can sail the cape dory in a very mediocre way and beat the j24 on corrected time if the j isnt sailing to its rating, which is derived from decades of competitive racing. Just because some people have won a local beer can phrf in a cape dory doesent mean much. The boat is still slow…which is fine if it’s the kind of boat you want to sail.Â
And also, its the internet, I don’t trust anything anyone says
Huckleberry181@reddit (OP)
Ahh now that makes sense, thank you!
Free_Range_Lobster@reddit
Powerful_Bluebird347@reddit
It’s relevant I look at it too. Yes it will be a lower rating if it’s a fast boats. Those are both slow boats.
It’s not just the weight it’s the rig size and shape and the hull design and length. What “lower numbers across the board” are you looking at?
Huckleberry181@reddit (OP)
The other #s in the post.. S/A, S#, and while I didn't put D/L in the post, those match the other two: 367 for the Dory, vs 170 for the Tanzer
Powerful_Bluebird347@reddit
In conclusion get a boat that consistently goes above 5kts any slower and it’s not the greatest.
ppitm@reddit
Sail area:displacement ratio will tell you so much more than PHRF. With due consideration to waterline length and keel type.
millijuna@reddit
All I know is that my boat’s PHRF is so high that if I can physically see my competitor when they cross the line, I’ve won.
Shorelines1@reddit
PHRF has a limitation (I was going to say handicap lol) in that it doesn’t have a formula for considering the windspeed.
Each boat gets one number. In my area, I tried to introduce a method for measuring the wind and factoring that into the corrected times, so that the heavy boats wouldn’t win all the races that had heavy winds and the light boats wouldn’t win all the races that had light winds. I couldn’t get it across the line.
So when considering the handicap differential between two boats, look at the weight to sail area ratio and consider the average wind speed where you want to be sailing or racing in.
If you really want to compare the difference two boats consider what you’re using them for and where you’re using them as part of your research. Based on your original post, OP, you look like you’re up for that. Many aren’t.
RedditIsRectalCancer@reddit
The cape dory is going to be roomier and more comfortable in a seaway. Given your goals, I would think that's the boat for you.
tench745@reddit
Regarding the comfort ratio, or more specifically the comfort of a boat. Stiffness doesn't necessarily make a boat comfortable. Less rolling is more comfortable, but that's not all that matters. A stable boat rolls less, but if the beam, displacement, and weight aloft are in the right combinations you can get a sharp, quick roll as the boat rights itself which is very unpleasant. A more comfortable boat tends to have a slower, gentle roll. I imagine the Tanzer falls more into the stable but uncomfortable side than the Cape Dory.
H0LD_FAST@reddit
A difference in phrf of 50+ indicates the boat is relatively faster. But a difference of 210-220 is effectively the same from a racing comparison, but that’s not very helpful to determine how the boat actually sails. Looking at the hull design, rig options, and sail plan of the boat will tell you that.  Displacement/lengh is the ratio to actually tell you how fast it is (or how much better it will move in light air) Comfort ratio is a useless number.
Away_Suggestion_9471@reddit
Don't buy a Cape Dory for racing unless you do really long races.
Huckleberry181@reddit (OP)
Racing is not my focus at all, but looking for a comfortable boat that can do coastal cruising. Both of these are capable for that; they've both crossed oceans.. just trying to make sense of all the #s, not just PHRF. That one being the only similar one out of the group is what has me confused.
GunnarSilverTongue@reddit
1977 heritage Morgan west indies 36 monohull there's only 12 left afloat of the original 40 built but their extremely fast and comfortable to live on as well trust me you'd love it if you want a transatlantic boat with spd included with comfort for long distance sails mine is amazing i pull 9 to 10knts under sail and 7 to 8 under power from her engine but I don't race just liveaboard and cruise but it's definitely worth a mention being designed by Charles Morgan
Away_Suggestion_9471@reddit
Having sailed/owned a Cape Dory I can tell you that boat will take care of you beyond when you can take care of the boat. Ignore PHRF, it's a contrived number.
Raneynickelfire@reddit
...especially if you're in Lake Erie.
phrf-le is [spits on dock].
Huckleberry181@reddit (OP)
The Cape Dory is prettier, but she's appears to need more work as well, which might be a dealbreaker.. we'll see this weekend.
Everyone's focusing only on PHRF, which is not what this is supposed to be about.. just confusing how that # can be so similar while all the others are so different.
jeffeviejo@reddit
FWIW, PHRF for Catalina 22 is 270, Cape Dory 22 is 220.
Huckleberry181@reddit (OP)
Are the Cape Dory hull designs just much faster than their calculations would suggest then? Because going by the other #s for those two boats that doesn't appear to make any sense either.
jeffeviejo@reddit
They're considered slow on short triangular courses. Once they start moving, they'll keep moving. Long distance sea kindliness is where they shine.
bbcwtfw@reddit
PHRF numbers are made up, not calculated. They are heavily influenced by who raced the boats, and where. A boat with an active racing fleet in an area that favors that boat will end up with a fast rating because it's being sailed by experienced and efficient crews. A boat that is rarely raced and only by people dabbling in racing their cruiser can end up with a very slow rating.
If you were going racing, which you aren't, you'd consider the PHRF rating before buying a boat so you don't stick yourself with a boat that has been raced actively by fast crews such that you'll never be able to sail to the high bar they have set. That's what people mean by not being able to sail a boat to its rating.
diekthx-@reddit
Ratings give you an idea of relative performance. ORC certificates give you more information, but you won’t find them for the smaller boats. The problem is, and these posts here kinda talk around it, is that whatever small boat you’re buying, it’s probably going to be very slow unless it can at least plane. So ergonomics matter more than ratings and there are no numbers for those.Â
Huckleberry181@reddit (OP)
And therein lies the confusion. Everyone on this post is only focusing on PHRF, while the question is how can that/ relative performance be so similar while all the other calculations are so different? S/A, S#, and D/L.. unless none of those mean anything, which I kinda doubt.
diekthx-@reddit
PHRF is (supposedly) an empirically derived number based on actual performance of boats on the race course. The fact is the other numbers don’t mean much in terms of hydrodynamic performance. I would recommend reading https://orc.org/measurements/hull
Obviously sail area matters as well as mast height. Rig type too. I’ll note PHRF ratings assume new sails btw. The comments about some boats not being able to sail to rating apply in some weird cases where either the boat can plane downwind or the rating committee are malicious or incompetent.Â
Zealousideal-Ad-7618@reddit
Attainable Adventure Cruising have just started a series of articles on exactly that subject - they have loads of great content, well worth paying the small subscription fee:
https://www.morganscloud.com/2026/03/26/choosing-the-right-cruising-boat-part-1-size-power/
CharterJet50@reddit
Racing is the only reason to care, and even then phrf is kind of a silly game of math that we play anyway. If you really care about racing get a one design that’s raced in your area.
Huckleberry181@reddit (OP)
I don't care about racing at all.. at least not yet. Want a solid cruising vessel which they both appear to be. Just trying to make sense of all the #s, and all of them being quite different except PHRF is what has me confused.