We are often asked “I can't get mahogany, white oak or spruce; can I use?”
Boats have successfully been built using all sorts of woods that are not recommended for boat building. But when we're asked to recommend a wood or alternative wood, we pick from a standard list. In our plans, we don't generally list long-leaf yellow pine as an option, because it's not available here. It fact, it is a good option and frequently used as an alternative to white oak. Like Douglas-fir, there are caveats about yellow pine. Both woods, in the areas where they are common, are used for home construction. Construction grades are NOT acceptable for boat construction, both from a quality standpoint and because they are not properly dried. Yellow pine is also a generic term which encompasses a variety of woods. The experts recommend "long-leaf" and some specify "old growth”. "Straight grain" is specified for many types of wood, particularly Douglas-fir, because it is dimensionally more stable and has better strength characteristics.
Before the 20th Century, when wooden boatbuilding (like many crafts) was an art, boat builders would take great care in selecting their lumber. Today, in a world of consolidation of suppliers and rushed life styles, many home boat builders contact us to ask if they can use woods that really aren't suitable for the wet environment in which boats spend much of their life. In many cases, the caller had visited their local building supply store and found that specialty woods were not available. The proper woods may have been available in lumberyards or from local specialty suppliers, but they had not taken the time to look. "Can I use red oak instead of white oak?" Red oak is not as rot resistant as white oak and is not recommended... but can it be used? As Allyn (our now retired shop foreman) was fond of saying, "It ain't my boat". We can give recommendations, but it is up to you the builder to decide what to use.
Which non-marine woods could be substituted depends on how the boat will be used. You always want wood that is properly dried, free of knots or other structural defects, but what if this is a duck boat you keep in the garage and only take out a couple of weeks a year? If it is well painted, do you really have to worry about rot? Probably not. Clear red oak would be an option, albeit heavy for a boat you might have to carry any distance. Western pines tend to be relatively weak and prone to rot. If you are building a small rowboat that you use as a coffee table, pine would be fine. If it's kept inside and only taken out occasionally... how about used frequently, but stored dry in a garage… how about stored under a cover in the back yard? When you build a boat and you know how it is built and what its limitations are, then presumably you will treat it accordingly. But, if you give it to someone else who hasn't decided in advance the limitations he would accept, your pine boat may be very short lived.
We have a section on our website - Wood & Plywood - pages in which we have reproduced Chapter 5 from our book Boatbuilding With Plywood. This chapter discusses woods used in boat building. If you will take the time to read it over you will find a wealth of information that will help you decide what species of wood to use in building your boat. Once you’ve read it you may even find yourself authoritatively passing along to others building their own boats why (or why not) a particular species of wood is desirable in their endeavor.