The old wooden ships were vulnerable to all the critters that live in the water and like to eat wood. So the builders covered the bottom with copper plates. There are a couple of different approaches to doing this on a model. I decided to use the adheasive-backed copper foil tape that is generally used in stained glass applications. Here's how it works. The hull is nearly covered here:
The copper foil comes in a roll.
Roughly measure a length to install.
Then put the copper strip into a "jig" to hold it in place upside-down.
Next, cover it with a strip of wood that's a little narrower than the copper.
Then, use this handy pattern making tool to "dimple" the foil from the back.
The effect is almost looks like rivits.
Now, a little more detail every half inch.
Looks a lot like copper plates.
Peal off the paper backing and apply the copper strip to the bottom.
Use a sharp blade to cut off the ends.
After a few more strips, the bottom is completely covered.