So you are trying to convince us by showing us alumimum boat manufacturers and owners? Your sources are biased..
So what does the US Government say about Alum boats?
"Aluminum weapons systems are in widespread use throughout all services of the military. Unfortunately, more and more failures of aluminum due to corrosion are being reported. "
Aluminum Equipment Failures in Coastal and Marine Environments
How about this 144 footer that failed in 1 month??
"Nichols discovered the cracks in the Jet Cat's hull after the boat's owner, Catalina Express, noticed the aluminum on the boat discoloring. Just a month after the 144-foot boat was launched by Nichols in April, the problem caught the attention of the company's engineers. Metallurgy tests showed that the aluminum was defoiling wherever it was in contact with salt water. Cracks near the Jet Cat's engine room were so large that water had begun to seep into the boat."
Cracks in aluminum boat's hull cause concern at Nichols - South Whidbey Record
Here is what the everyday guy says about alum boats:
"I have a crack in my boat. The boat is a flat bottom boat and the crack is where the side meets the bottom. I am sure that the crack can be welded no problems and stop the leak. I am drawing a blank on who to take it to to have it welded up tho. The crack is about 9 inches long"
Aluminum Boat Repair
Then there is this guy:
"The boat has been in use constantly, most likely with these welds cracked for many years"
Aluminum boat - Cracked welds - Page 1 - 367412
Here is another guy:
"What I found are 17- 2" welds over a 10ft. length from passenger console to bow broken. "
The Marinette Forum:
"Check the hull first before you decide to weld. Aluminum hull percussion sounding or ultra-sounding can cost $20.00 per foot to find flaws, ask a surveyor who knows this stuff.
If it feels deeply pitted, it's too far gone, see below. A small patch is usually just fine. "
Another discussion about older alum boats:
"Many times I have seen older riveted alum. boats crack along and near the rivets. I don't think that the crack can be repaired."
This one even has pictures:
"Here are pics of the crack. If anyone can please share on any reinforcement tips and how anyone repaired a cracked aluminum transom. Thanks everyone."
Lets see what wikipedia has to say:
"One important structural limitation of aluminium alloys is their fatigue strength. Unlike steels, aluminium alloys have no well-defined fatigue limit, meaning that fatigue failure eventually occurs, under even very small cyclic loadings. This implies that engineers must assess these loads and design for a fixed life rather than an infinite life."
For every post you can find positive about aluminum boats, I can find a hundred that talk about fatigue cracks in any alum boat of every size imaginable. I am one of those guys with a 12 foot alum/glass fishing boats with fatigue cracks in the alum seats.
Now I can easily also go out and find glowing reports on wood, steel, fiberglass or concrete. But we can also point out the negative aspects of these materials.
I think my most fundamental point is, consider that every building material has some particular issue. Aluminum is no different. The way I see it.. the most attractive aspect of aluminum is its light weight.