Z:
You say: "I constantly get told steel is better than aluminum always and vice versa making it hard to imagine an accurate theoretical comparison. "
I am not surprised :-)! The choice between these two materials seems to be made, generally, on the basis of ideology rather than reason. That is why you should NOT be guided solely by opinions expressed by owners of boats of either material. Take their views into consideration, of course, but do not act on them until you understand the pros and cons of each material fully.
It may interest you to know that here on the
West Coast of
British Columbia, where the salmon fishery once thrived, Sam Matsumoto, who had been building wooden
fishing boats since the end of the Kaiser's War, began in the late 1960s to build his boats entirely from aluminum. I do not know what alloy he used, but I
recall his saying that he could cut it with wood-working tools and that it was really, really easy to weld. Sam built dozens and dozens and dozens of aluminum
fishing boats, and a great many of them are still around this half century later. They required no painting above the waterline because the natural oxidation of the aluminum was self-limiting. Once oxidation reached a certain extent, it would cease. The "bare metal" appearance of the boats was unusual for the time, but actually rather pleasing. Now we see such boats every day, and their appearance has become part of the "Salish Sea Look"
I had the honour of being invited to the launching of Simon Fraser University's archeological
research vessel,
Sisiutl, at Sam's yard (Matsumoto Ship Yards, in North Vancouver) in 1972.
Sisiutl was 37 feet and accommodated a dozen archaeology students and a prof or two on "field trips" on the
West Coast of BC including the difficult, dangerous Pacific side of Haida Gwaii. The university
sold her "out of service" in about 1995, and she has gone through a number of owners since. She is still active, owned AFAIK by a lady in a distant suburb of
Vancouver.
From MY perspective, therefore, having seen so many aluminum boats last a half century and still be going strong, it is no contest. The aluminum boat wins hands down against the steel boat EVERY TIME, because, when built from the right alloy, they simply DO NOT RUST. In consequence a second hand ally boat is a far safer bet for a
novice seafarer than is a steel one! Less risk, less
maintenance required, thus less costly to maintain.
A couple of other points:
The material that a boats hull is made from is of no consequence for the boats performance. Two hulls having the same lines and having the same displacements will perform identically regardless of their being built from different materials.
The construction cost of a boat's hull amounts, generally, to something like 10% (perhaps a little less) of the "fully found" cost, i.e. of the cost of the boat ready to go to sea. Assume now that materials and labour costs are 50/50. This means that the materials cost for the boat is only 5% of the "fully found" cost. If, now, ally is twice the cost of steel for the quantity required, the impact on fully found cost is only 2.5%. This should have no influence on the asking price of a "mature" boat.
Finally, I see no reason to eschew "frozen snot" - "fiberglass". Impact resistance obviously only comes into play for such as cannot navigate well enuff to stay off the rocks! So, IMO, the argument that "steel is stronger" is entirely spurious. Ditto aluminum!
However: Anyone can learn to do a tolerable
repair of fibreglass. Perhaps not a pretty one, but at least a tolerable one. It is not true that anyone can learn to do a decent weld. But recognizing that, I would think that if you really mean to do what you say you wish to do, and do it in a metal boat, you should learn, if you don't know how already, to do a decent weld. In my opinion, tho' I've only tried my hand at it a few times, ally welding is easier than steel welding. And I would think that welding supplies, including the gas, are available in even the most
remote corners of the inhabited world these days.
All the best to you.
TrentePieds