Hi James:

My personal preference is aluminum, especially in the size range you are discussing. Alum. is lighter, easier on maintenance (especially if you leave it bare), will have a lower center of gravity, and of course, perform better under sail and power. Where steel has an advantage is in impact resistance–however, assuming you are designing to the same scantlings, there will be little difference in most situations. The one issue which scares people is the threat of electrolysis. This is a bigger issue with alum. than steel. However, we’ve been doing alum. boats for 20 years now and have yet to see a major problem–as long as the boats are correctly wired–and care is taken with shore power (i.e. an isolation transformer is used). You will find a much more detailed discussion of the pros and cons in our Offshore Cruising Encyclopedia. Regards -Steve Dashew