The goal is to have a float sort of like a mooring buoy that supports a lot of weight and is long and skinny. However, instead of round I would like to have a wing shape so it can move through the water more easily while lifting the load. Part will stick out of the water so it has a relatively small waterline area and does not react to suddenly as waves go up and down. We want to use 4 of these to float a home that can move slowly through the water on solar power.

The picture at the right is 300mm by 1200mm by 7 meters. The weight would be attached to the bottom and maybe half of this would be under water and half sticking up in the air.


There are large aluminum extrusions with a similar shape to what I would like for my floats, for example:

But I would like mine more wing shaped, like:

This wing shape would let the float slide through the water with less drag and make it act like a keel or daggerboard. With this the seastead could resist strong winds while using little power.

The question is how large an extrusion can be made. Ideally we could get 1,200 mm wide and 300 mm high but even smaller sizes would be interesting.

However, the largest I have found so far is 800mm wide and 120mm high.

I am trying to find out:

  1. The maximum sizes for width and height
  2. How long extrusions could be. Nice if 8 or 10 meters
  3. The cost to make the die
  4. The production costs. Is price per Kg? Mimimum number?
Of course we want a marine aluminum alloy.

Note that I am very flexible on the tolerances. We are making a float that can move through the water, but if it was not exactly the same shape every it would not matter.


Could extrude rubber in this kind of shape maybe:

Foam with covering

Or maybe extrude this shape in foam and then cover with something stronger like polyurethane.