If Money were no object....

Thanks for the edit. After writing the following load of blethers, I went back and looked at the links.

The only good reason to choose 90-10 CuNi is resistance to fouling and corrosion. The strength and stiffness are mediocre and it has slightly higher density than steel. The most studied hull that I am aware of was the Copper Mariner. They addressed the cost and strength issues by cladding steel with a relatively thin outer layer of CuNi. That worked because the cost of CuNi was much lower at the time. Monel is roughly 60-30 NiCu and an active passive material much like stainless steel or titanium. The passive oxide film is a thin, tightly adhered oxide that is non-toxic to fouling. The fouling organisms adhere just as strongly to Monel as they do to most things. No problem. If cost is no object, the hired help can haul the boat, clean the hull and apply the anti fouling while I jet off to a nice resort.

When bare, 90-10 is toxic to fouling organisms and has a very low corrosion rate just like most copper alloys. As is corrodes, it forms a unique laminar structure of alternating layers of bacterial(?) organic film and metal oxides that has very low shear strength. Once the film is thick enough to reduce the toxicity of the surface it will foul like any other material. The fouling organisms however are attached to the outer surface of the laminar film that is only weakly adhered to the underlying metal. When the Copper Mariner was laid up for repairs, it fouled just like any other boat in Nicaragua. After the repairs were completed it was put back in service without cleaning the hull. The fouling sloughed off shortly after it got underway. Within a few years, the Nicaraguan government also sloughed off and INCO lost track of the boat as I recall.

If cost was no object, I would still consider the possibility that the situation might be temporary. I would build a nice wooden sailboat with a heavy keel. Platinum ballast is a good choice since it is very dense. If my circumstances were to change, I could always recycle the keel, replace it with lead and sail away a rich man once again.

After typing this load of blethers I decided that if I were to post it I should check my facts. It was the Copper Mariner II with the clad metal. I was also unaware of the Asperida. A quick search on the copper. org site will bring up a lot of material on CuNi boats.