The Offshore Voyaging Reference Site

Hull Materials, Which Is Best?

As Phyllis and I think about what our next boat might look like, one of the primary decisions is hull material.

We have several chapters in this Online Book about the characteristics of the four general available options, steel, aluminum, wood and fibreglass (see Further Reading below), but that still leaves the question: Which is best, not just for Phyllis and me, but for you, too?

As usual, the answer is the oh so annoying: it depends on what we plan to do with the boat.

But what I can say, is that there are two materials that are pretty easy for Phyllis and me to drop from the hull materials prospect list. So let’s start with that, and then move on to the two left standing to pick a winner.

Hull Material We Won’t Consider

We will not even be looking at boats made of steel or wood—not quite true, we might consider a good wood epoxy saturation build—and that’s also our advice to most of you.

Why neither of those two materials? Both are intrinsically unstable. Or, to put it another way, no matter how well the boat is built, if left to their own devices, wood will rot and steel will turn into a pile of iron oxide.

OK, before you take me to the woodshed in the comments, let me make clear that I understand that good boats can be built of both wood and steel.

One of my good friends has a wooden boat that has given great service (including a bunch of ocean crossings) for decades, and will continue to do so for many more. But he built her himself, has cared for her meticulously, and has incredible skills. But I’m not Wilson (that’s his name) and, in all likelihood, neither are you.

The same applies to steel. If you built the boat yourself, or supervised every step of the build, and then cared for her yourself, it can work. Just look at the amazing voyages made by AAC contributor Trevor Robertson in Iron Bark.

But we are talking about second-hand boats for most of us, so steel and wood are out because it’s difficult to be reasonably sure in a pre-purchase survey on either material that something horrible is not going on deep within the structure. Something that, when discovered, can turn our new-to-us boat into a worthless pile of junk—we are talking the risk of serious wealth destruction here.

Still not convinced? Let’s dig deeper.

There’s another big problem with wood. If we find say a rotten stern post, or any other structural member after purchase, the skills and time to replace it are prodigious. Heck, just replacing a single plank in a way that will actually be watertight takes great skill and perseverance. Way beyond practical DIY for most of us. And I have seen professional replacement of just a few rotten members in a wooden boat cost over US$100,000.

What about steel? Well, on the positive side, repairs require less skill than wood. But the problem is it is very difficult to build a boat of steel under about 45 to 50 feet that will sail or motor well. The reason is that steel plating must be of a certain minimum thickness to be workable and not deform, regardless of boat size, so small steel boats are pretty much always too heavy, at least for the performance that Phyllis and I want.

And, finally, the maintenance of a steel boat is simply no fun—unless you have some perverted love of chipping rust and working with toxic chemicals—and to make that worse, any breach of the coating must be dealt with promptly and properly.

The bottom line is that I know a lot of people who own a steel boat, or have done so in the past, but I have never met anyone who has owned a second steel boat.

All that said, I guess purchasing a steel or wood boat with a history like those I mention above, from someone you really trust, would be OK—particularly if you make clear that if they have lied to you, you will hunt them down and… And the advantage of this course is that you can often get a lot of boat for very little money.

But be careful…really, really careful. And know that you have consigned yourself to a heavy maintenance burden for as long as you own the boat, as well as taking on a boat with a resale value that could easily go to near zero.

Hull Materials We Will Consider

Where does that leave Phyllis and me, and probably you, too? Yup, with fibreglass and aluminum. Both are intrinsically stable—assuming we don’t do something stupid, and, when built right, a hull of either does not deteriorate just because of the passage of time.

And both can be surveyed prior to purchase to make fairly sure (there is no certainty) that there is not something horrible lurking. Yes, I know there are many horror stories (I have one of my own) about fibreglass boats with hidden faults, but that’s a survey failure, not a material one. (More on how to avoid survey failures coming soon.)

So which is best, aluminum or fibreglass? Brace yourself. I’m going to do it to you again. It depends on what you want to do. Let’s look at each.


As a 30 year aluminum boat owner, I love the material. And if Phyllis and I were planning to go to seriously hazardous places (as we have in the past), aluminum would be our only choice.

There is simply no other material that can match the combination of strength-to-weight ratio, impact survivability, stiffness, and keeping those characteristics for decades, all without the horrible maintenance load of steel. This is probably the reason that by far the majority of experienced high latitude sailors that we have encountered over the years have aluminum boats.

But on the other hand, aluminum is a bitch to keep paint on, an expensive bitch. And, by the way, don’t think for a moment that leaving the hull bare solves that. Prepping and painting the deck and cabin of an aluminum boat to the yacht standard that many owners want and want to maintain, will, if done right by professionals, cost as much or more than painting an entire fibreglass boat.

The point being that if you are considering aluminum, you need to do as I do: take your glasses off when you see the paint bubbling. Or, better yet, seriously embrace the industrial look and have no paint on deck or hull, other than non-skid.

Also, although there is no question that most of the horror stories you hear about aluminum are just that—stories—the material does require caring for, including closely supervising anyone who works on the boat. Most boatyard professionals are dangerously ignorant about aluminum and many will make that worse by not appreciating their own ignorance.

All that said, if you want the ultimate voyaging boat built in the ultimate material, and you have some big bucks to spend, buy a Boreal 43/47 in aluminum, and be happy. And you may be able to buy a good used Garcia or Ovni for much less.


So that leaves fibreglass. And for Phyllis and me, who now want a boat that we can safely leave unattended far from home—we are now part-time cruisers—that’s the way to go.

Also, as we age further, we will be paying boatyards to do more and more for us, another plus for fibreglass, since it’s more resistant to unsupervised ignorance—boats with core in the hull, particularly balsa, not so much—than aluminum.

Bottom line, if you are not willing to learn the basics of aluminum boat care and won’t be constantly present to rigorously enforce that knowledge on others, choose fibreglass. On the other hand, the good news is that said aluminum boat care is not hard, and not magic. See Further Reading for our complete guide.


So, to wrap this up, when buying a second-hand boat, good old frozen snot is the baseline and aluminum the ultimate, but with caveats. As for steel and wood, the great majority of us should not go there.


I’m guessing that many of you steel boat owners are now seething and reaching for your keyboards to tear me a new one. Feel free to disagree and tell me why steel is great, but be realistic.

And please keep in mind that we have a lot of readers who do not have a lot of boat ownership experience. So if you blow sunshine about the issues with steel boats, particularly old steel boats, you may make yourself feel better, but you may also tip someone into a life altering decision with substantial negative consequences. Not something any of us need on our conscience.

Further Reading

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 1, How We Shopped For Our First Cruising Sailboat
  35. US$30,000 Starter Cruiser—Part 2, The Boat We Bought
  36. US$30,000 Starter Cruiser—How It’s Working Out
  37. Q&A, What’s the Maximum Sailboat Size For a Couple?
  38. At What Age should You Stop Sailing And Buy a Motorboat?
  39. A Motorsailer For Offshore Voyaging?
  40. The Two Biggest Lies Yacht Brokers Tell
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