The Offshore Voyaging Reference Site

Learn From The Designers

Over the years I have written (some might say ranted) a lot against the evils of poor yacht design. And with justification, since there are few things sadder than a boat that doesn’t sail or motor very well, no matter how much power (engine or sails) we throw at it.

After all, we do this for fun, so surely we all want the pleasure of knowing that our boat operates in an efficient way in the medium she was designed for. And even if we don’t care, a good hull design is both more fun to sail or motor and safer—slow increases our exposure to bad weather, reduces manoeuvrability, and increases the load on the gear and crew.

But the sad fact is that many, perhaps most, boats out there have poor hull designs. I have already dealt with how that happens (see Further Reading), so this article is about what we can do to avoid ending up with one of those woofers. As so often happens, I was inspired by a comment from a member:

I am struggling to apply this information into selecting a hull that is appropriate out of the universe of boats available on the used market (within my budget). For a newbie, what advice would you provide to help identify a good hull from bad. I am unable to find prismatic coefficient for the boats I am considering. Is there anything else I can use as a proxy? Max hull speed is sometimes available. I want to make the right decision…but I don’t know how.

So let’s start by answering his question: There’s no single number, shortcut, or even group of numbers that will tell us whether or not the designer did their job properly or, as so often happens, was persuaded to do bad stuff by others (almost always in an effort to cram too much interior into a boat).

And to make things even more complicated, good design is a moving target depending on how each of us intend to use the boat.

Given that, there are only two ways to avoid buying a bad boat:

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More Articles From Online Book: How To Buy a Cruising Boat:

  1. The Right Way to Buy a Boat…And The Wrong Way
  2. Is It a Need or a Want?
  3. Buying a Boat—A Different Way To Think About Price
  4. Buying a Cruising Boat—Five Tips for The Half-Assed Option
  5. Are Refits Worth It?
  6. Buying a Boat—Never Say Never
  7. Selecting The Right Hull Form
  8. Five Ways That Bad Boats Happen
  9. How Weight Affects Boat Performance and Motion Comfort
  10. Easily Driven Boats Are Better
  11. 12 Tips To Avoid Ruining Our Easily Driven Sailboat
  12. Learn From The Designers
  13. You May Need a Bigger Boat Than You Think
  14. Sail Area: Overlap, Multihulls, And Racing Rules
  15. 8 Tips For a Great Cruising Boat Interior Arrangement
  16. Of Cockpits, Wheelhouses And Engine Rooms
  17. Offshore Sailboat Keel Types
  18. Cockpits—Part 1, Safe and Seamanlike
  19. Cockpits—Part 2, Visibility and Ergonomics
  20. Offshore Sailboat Winches, Selection and Positioning
  21. Choosing a Cruising Boat—Shelter
  22. Choosing A Cruising Boat—Shade and Ventilation
  23. Pitfalls to Avoid When Buying a New Voyaging Boat
  24. Cyclical Loading: Why Offshore Sailing Is So Hard On A Boat
  25. Cycle Loading—8 Tips for Boat and Gear Purchases
  26. Characteristics of Boat Building Materials
  27. Impact Resistance—How Hull Materials Respond to Impacts
  28. Impact Resistance—Two Collision Scenarios
  29. Hull Materials, Which Is Best?
  30. The Five Things We Need to Check When Buying a Boat
  31. Six Warnings About Buying Fibreglass Boats
  32. Buying a Fibreglass Boat—Hiring a Surveyor and Managing the Survey
  33. What We Need to Know About Moisture Meters and Wet Fibreglass Laminate
  34. US$30,000 Starter Cruiser—Part 2, The Boat We Bought
  35. Q&A, What’s the Maximum Sailboat Size For a Couple?
  36. At What Age should You Stop Sailing And Buy a Motorboat?
  37. A Motorsailer For Offshore Voyaging?
  38. The Two Biggest Lies Yacht Brokers Tell
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Ernest E Vogelsinger

John, I especially love your term “boat porn”, matches my feelings perfectly 🙂

I am doing what you mention for some years now, plus trying to sail on as much different boats/designs as possible. As I am not a rich guy I mostly crew on deliveries which offers a good spread between older and “modern” designs.

What came out for me until now is that, for my future boat, I will avoid those modern flat hull designs as they do not provide a smooth ride as soon as it gets rough, and I still need to discover the place where is wind but no waves.
Next I would want to avoid sleek external keels – integral and at least moderate long with cut forefoot would be my choice. The same with rudders – standalone pendulums will lose against skegged types.

I know this will not give me a racer and a boat that might be tricky in the harbour – but I prefer to stay comfortable and safe when out there to being able to effortlessly moneuver the marina. After all I plan to spend more time sailing than doing marina show-offs 😉

Marc Dacey

This is a very important point: If you find yourself gravitating to a certain style or type of boat, sail it for 24 hours in challenging conditions, preferably as delivery crew involving a 0300h watchstanding. Some excellent, “long-legged” boats exist: fast, beautiful thoroughbreds that can knock off 200 NM days with ease and safely.

But the “ride” may be unpleasant. It may not heave to easily. It may have insufficient stowage. Perhaps. There are the rare boats that can cruise fast and not crack your teeth. But not many and they aren’t generally cheap.

You may prefer a packhorse that will plod across oceans in comfort and utility. But you won’t know from seeing them cradled, although you can make some educated guesses with experience, and experience should involve sailing them in snotty weather.

Ernest E Vogelsinger

Thanks Marc, this absolutely concurs with my thoughts. For example, this year I crewed on an Oceanis from Tenerife to Spain, and while the Oceanis is a great boat to live on she was quite unpleasant in the atlantic swell when there was a small blow, and sometimes I felt like living on a surfboard. A couple of weeks later I delivered an old small Melody 34 from Sicily to Greece, and while she can be a bit uncomfortable for living (mainly because she is only 34′) there couldn’t be a greater difference in behaviour – steady and calm in the seas (well, except bigger waves overtaking from behind), smooth in the waves.
I also grew to dislike in-mast furlers – there was not a single trip where I didn’t encounter issues. And they are a chore when it comes to reefing in a sudden blow.

Scott Arenz

Hi John,
This is very helpful post for us aspiring cruisers and boat enthusiasts. Thank you for all the tips and book recommendations. The “information asymmetry” that exists between us beginners and those of you with many thousands of sea miles is not to be underestimated. Insight into the basics is always appreciated!

I’ve found the Offshore Cruising Encyclopedia by Steve and Linda Dashew to be great reading, although much of their hull design and equipment discussion concerns larger yachts. Some readers might not know that all of the Dashew’s books can be downloaded from their website:

Scott Arenz
Atlanta, GA

H. Christensen

Chuck Paine’s book is available in .pdf format, directly from him, for US $19.95: Boat porn indeed, best viewed on a BIG monitor.

For additional reading I would also recommend A good primer from an experienced, well-respected yacht designer, with quite a few examples of sensible cruising designs.

Paul Clayton

I’ll second (third?) Chuck Paine, his books are great and drawings of many of his boats are available on the internet. Another book that is a joy to read and worthy of close study is “Best of Uffa”, edited by Guy Cole. Uffa Fox was a renowned British naval architect and the book includes diagrams and short critiques of about 50 boats that he considered standouts. “Best of Uffa” is long out of print but used copies can be found at Amazon and other used book sellers. Boat design has come a long way since Uffa Fox wrote these articles back in the middle of the last century, but many of the fundamentals remain the same.

Timothy Jenne

Honestly this post is one of the best I’ve read on the subject. I get asked these questions all the time from my students. The Dashew’s have great boats if you can afford them; long & sleek. You’ve opened my eyes to a couple of French aluminum boats like the Ovni & Boréal which are lust-worthy. If I might add John Kretschmer Sailing a Serious Ocean which has a list of boats which are affordable and ready for open ocean, most of which he has sailed or delivered on the ocean over long distances.

Douglas Nelson

I really liked Kretschmer’s book too.

H. Christensen

Hi John,

As an addendum to all of the above, I would strongly recommend two more books by the inimitable Dave Gerr: “The Elements of Boat Strength” and “Boat Mechanical Systems”. Although neither book deals with hull design, both contain a wealth of information from an extremely knowledgeable guy who seems to have all his bolts torqued tight.

Either or both would be an invaluable resource for anyone who’s considering a boat, shopping for one, maintaining one, or (shudder) refitting one. The subtitle of “Boat Mechanical Systems” says it well: “How to Design, Install, and Recognize Proper Systems in Boats”.

For me, “recognize” was the crucial word. My wife and I hope to be seriously shopping for a boat this year, and I know we’ll be better armed thanks to Dave Gerr.

And, for whatever it’s worth, his rather clunky sense of humour appeals to me. It’s evident in all four of his books. 🙂

Hans (yes, that’s Hans Christensen. Too late to change my name now).

Kevin McNeill

I went one better, I enrolled at Westlawn, survived the experience until they wanted me to design the plugs for the interior of modern power boats. Then I folded my tent and went away, wiser with just enough knowledge to be dangerous. So I restrct myself to designing small boats, Bolgereque is you will.

Jesse Falsone

Since this article first published, there’s been a rash of YouTube sailing channels that purport to be run by experts in the domain of yacht consultancy. They promote designs suited primarily for cruising to the southern latitudes, and suggest that anyone can do it (even those who have zero experience). It is telling that the focus of these channels tends to be on the comfort of the interiors for living. They don’t discuss how the boat sails, motors, or their virtues and vices of inherent design compromises. Normally, I wouldn’t be so outraged by it because people are free to make their own decisions, but if these people were dispensing political opinions, medical advice, or histrionics, they would be held in contempt by the misinformation police and roundly canceled. As a recent subscriber, I appreciate that you emphasize what I’ve always known to be true about a proper cruising yacht – you can’t have your cake and eat it too.